I've just logged in with my Piefed account after seeing your post. Other than me accidentally tapping sign up instead of log in, there were no issues.

I'm on Piefed.social and used Bitwarden to autofill my credentials. I'm using Android 16 with Voyager 2.35 I think (I'll correct this once I've posted), and am using my home wifi with no VPN. I use Adguard Home and Cloudflare for my DNS, and am in the UK. I can't think of anything else that might make a difference, so I'll end my comment there 😋