Hello, Kevin, and thank you for your suggestion.
I already went through and downgraded, and now webP is working as it should. I think I'll hold off on updating to 2023 until later this year.
I also noticed that after the upgrade, I was seeing white flashing when opening up an image (and, yes, I did go into Preferences and followed instructions on how to remove that). But then I discovered processing webPs wasn't working and decided it was easier to just go back to 2022 than spend time troubleshooting further.