Hey
So there is an issue if you leave in EU,
there is a new law(I think it's a law) where you're not able to make a charge of ZERO in the banks even if it's for confirmation only
Don't know if google are trying to solve this somehow but I managed by getting Revolut as bank and after I got verified by them (free of charge)
then I had no problems with starting the free trial!
and I know this works for more than me because I told this to another person that had this problem and got it to work with same actions