It seems I did not try making a Lenovo account with the pm.me alias address. I did use a protonmail.com address when tried before swapping to making an account using a Tutanota address and attempting to replay the purchase sequence. I don't remember the conversation I had with support when they deduced the error to protonmail addresses not being eligible for purchases for not "being verifiable" despite the fact that payment and billing information is also provided in a purchase. I don't remember if the support technician claimed that the pm.me alias would also be blocked, but for some reason I never tried it.