Are any of these buyers asking for your email, or other scammy requests?
If not, it won't be your PP but Etsy's that might be the issue. Get your buyers to check their PP or contact Etsy directly. Let them know that sellers with Etsy payments do not handle any payment transactions.
edited to add ... I'm in Australia and was able to go right up to the 'almost purchasing'. It could be an issue with your buyers' accounts ... or it's a variation on the ongoing scam pandemic.
