We have been stuck at CiviCRM 5.12.4 for months now. I have had issues with my Contribution page (details not needed here) as I tried to upgrade through Civi 5.14.2. So, I held off until today to try one more time on the latest stable release (also to avoid the critical warning that 5.12.4 is OBE that scares our staff).
We are running WordPress 5.2.3 and use iATS Payments 1.6.2.
This is the behavior. If I am logged into Wordpress, when I click on a contribution page, both the contact info and the billing name and address are correctly filled in. However, hardly any of our visitors create and use a WordPress login. If I am not logged in, the page does NOT have the "My billing address is the same as above" checked by default as it did before. Worse yet, if I check to use the same address for billing as for contact, it does not propagate. Someone would have to fill in every field all over again. I think this "almost" works, but am wondering what could possibly be wrong. It seems like an issue with the handler for contribution pages, as the behavior seems to change every time I try a new version.
I obviously am not going live on our main website with this behavior. If anyone would like to observe for themselves, please visit https://test.sdcbcdream.org/join/ . To see it work correctly (5.12.4), you may visit https://sdbikecoalition.org/join/.
Thanks for any help. This one has me stumped as we have always had no issues moving forward with stable versions.