Anton, I've another problem with the redirect, after the payment has been done in stripe test mode. My UNA system doesn't redirect properly and I get a http error 500. The level that should be upgraded stays the same in UNA, althoug in stripe panel it shows a successful transfer. What did I miss, do you have an idea? Pics attached.
Thanks for checking my server, LeonidS. So far we know, that I have to talk to my server host, since I run UNA on a shared virtual server environment, that might prevent modules from functioning as expected.