Probably a bad motherboard but the UI and the way they did things made me scratch my head.
I returned it and bought a Samsung S21+. So far I love the thing! (as I knew I would.) It's like my S9+ only better in every way.
Pixel 4a 5G and S9+ vs the new S21+.
S21 likes:
No more crap bixby key. (you can choose how it works now completely.)
Better battery life.
Better cameras.
Better screen.
Way faster charging.
Better fingerprint reader.
I like Samsung's UI vs. stock android.
Bigger screen vs the other two.
Good construction.
These new phones no longer come with the power brick which is hella annoying but I heard it accepts the 45W chargers so that's neato.
I thought the Pixel's 18W was nice. lol
Over I highly recommend the S21+ if you can afford it. It's a damn nice phone.
Too bad they only had purple.