Chances of 5 year visit visa for Syrian national

[Dani88]

My friend has a Syrian passport and has a German resident visa. They have already had a 6 month UK visit visa and visited twice without issue. This visa has now expired so they want to apply for a 2 or 5 year visit visa. There is obviously a big cost difference between 2 and 5 years. They want to at least try for 2 years, but if they had a good chance to be granted 5 then they would rather apply for that. Does anyone know what are the chances of someone with a Syrian passport being granted a 5 year visit visa? Does it ever happen? They have a good job in Germany and they just want to be able to visit their partner in the UK.

[Zerubbabel]

Try another 6 months and it goes well, 2 years.

I don't believe in jumping straight to a 5-year visa given the circumstances your describe.