It's 1 a.m. when Valentina Sanchez's alarm goes off. There's perhaps time to make a quick coffee and sweep aside notes to make room for a laptop on the table. Then the 24-year-old is straight into her first lecture of the day.

All her classmates are sitting in a room at Berlin's University of Applied Sciences, at a more favorable 9:30 a.m. But Sanchez is trapped back home in Puebla, Mexico. She can only watch the classes over Zoom, her face on a laptop screen placed on a table by other socially distanced students.

Read more: Mexico 'flying blind' in pandemic response

On the other side of the world, Roozbeh Irandoost is battling other issues to attend classes at the Dresden University of Technology from his bedroom in Sari, northern Iran. 

The time difference isn't as bad — he's only 1 1/2 hours ahead of Germany — but Iran's poor internet connection and blocks on websites such as Zoom and YouTube make following lectures much more difficult. 

Ultimately, both Sanchez and Irandoost have the same problem: Neither can get an appointment at a German embassy for an interview to secure their student visa, nor can they find out when they might be able to get one.

Students facing 'pressure,' 'uncertainty'

They are not alone. Hundreds of would-be master's students in Mexico and Iran are in the same situation.

When the coronavirus pandemic sparked worldwide shutdowns in March, German embassies stopped taking almost all visa appointments. Seven months later, in Mexico City and Tehran, the appointments still haven't restarted for master's students. 

"We are trying to contact the embassy every day," Sanchez told DW over the phone. "But most often we get no answers, and when we do, they cannot tell us when they will reopen for our appointments." 

"The uncertainty and the anxiety is the worst feeling. You just keep writing and hoping they will give you an answer soon."

Read more: Iran's coronavirus strategy divides health experts, government

"We have several social media groups [in Iran] and no one has a visa appointment," said Irandoost in a call. "We understand the pandemic is a big problem, but we can bring negative tests, wear masks and face shields. 

"We are facing so much pressure and have no news."

Other German embassies have acted

Up until a month ago, Iranian and Mexican students had support. Hundreds of other master's students from Nigeria, India, Colombia, Bangladesh and Turkey with offers from German universities were in a similar situation. 

They joined together online, using the hashtag #EducationIsNotTourism, to bombard embassies, ambassadors, the German Foreign Ministry and Foreign Minister Heiko Maas with messages, urging them to offer clarity on visa appointments. 

Read more: COVID-19 breaks study in Germany for African students

For some, it worked. The embassies reached out to students and began finding solutions. The German ambassador to India posted a video to social media, personally addressing students and updating them on new embassy measures. 

Students in Mexico and Iran, however, claim they have at best received sporadic stock replies, or nothing at all, despite numerous tweets and emails. 

"I received a university offer in July and immediately tried to get an appointment, but got no reply," said Mehran Mirmiri, 27, from Tehran. He is hoping to study music therapy in Heidelberg. 

"I have written 15 emails since then and I have had no response, not even a yes or a no. I don't know why it's so hard."

Students making sacrifices for studies

There's a lot on the line for the students. Many gave up their jobs in expectation that they would be in Germany by now, and some can't work because they are having to try and attend classes online. They have €10,000 ($11,800) stashed away in locked accounts to prove to the German government they can support themselves — but it's money that they can't touch.

Additionally, expensive language test certificates, proving they have an adequate level of English for international courses, are time-limited and running out.

"It was a really big effort for me and my parents to pay for this," said Sanchez, "and it's so difficult when your plans get disrupted and so much money is involved." 

Read more: International students made to wait months for German visas

In Iran, the situation is arguably worse. The currency is struggling, making studying in Europe more expensive by the month, and male students have only six months after finishing their bachelor's degree to move abroad before they're required to start 24 months of military service. 

"I only have two months of the six months left before I have to join the military," said Mirmiri. "I sold my home to support my studies and the economy here is not stable." 

"It's very stressful. I need to tell the military what is going on."

German government blames safety measures, logistics

The students don't feel like the embassies are following German government advice. "Foreign students who can prove that their studies cannot be carried out entirely from abroad, for example, due to compulsory attendance, can enter the country to begin their studies," Research Minister Anja Karliczek said in an August statement.

They are also frustrated that other countries hit hard by COVID-19, such as the United States and Brazil, have not closed visa appointments to master's students. 

"Whether and when an application or visa can actually be applied for or issued in such cases remains a matter for the local situation," said the German Foreign Ministry in an emailed response to questions from DW.

"As a result of the dynamic pandemic in Mexico and Iran, the embassies' ability to work has already been considerably reduced since the spring for reasons of infection protection for visitors and employees." 

The statement added that the ministry is working to ensure students receive visas, and said in total 310 academic visas had been issued in Mexico City and Tehran in the third quarter of the year. That figure, however, is not specifically limited to master's students.

Back in Puebla, Sanchez is hoping that number soon includes her. "I chose Berlin because I want to help make a change in the world," she said. "I just hope the German government can see that."