Ah. That's a curious problem. (I do not have a Proton email by the way)
From a quick browser search, it does looks like Proton may have problems recieving verification emails per Reddit. One suggestion was to manually assign "Allow" domain to filter for the missing verfication email -- so perhaps that might work.
(domain is the part after "@", so like gmail.com or whatever domain the tapas verification email comes from)
Otherwise, you can try contacting Tapas for help?
