Comment by twiss

Well - note that OP uploaded a key to keys.openpgp.org, and then seemingly forgot about it and lost the private key (or at least they couldn't decrypt encrypted emails, and their email client - not Proton's - showed them as being blank). So it's not a scenario that we explicitly tested for, and not something we can unilaterally fix completely - although we can try to make it clearer for the recipient why the message was encrypted and with what key, of course.