I recently went from an S6 with Verizon to an S20 5G with Google Fi. Since moving to the S20 I could no longer deposit checks using the Bank of America app. I found a solution and report it here as a public service.
The app said Use a darker background (I don't have anything darker than all black), Move closer, Closer than that, Whoa! Not that close, or today, for the first time, Couldn't read NFC tag. It took the picture as usual, then showed the check's photo as it used to do, where it looked fine to me, then in less than a second replaced the check photo with a red no-go sign.
I rebooted (I mean a cold start); wiped the cache and rebooted; did "update all apps" and rebooted; went into developer mode to turn sensors off and rebooted; checked camera settings for document mode and auto HDR and rebooted; uninstalled the BofA app and rebooted; reinstalled BofA and rebooted; maybe I'm leaving out something I did, but after I did it I'm sure I rebooted. All these things I did at the suggestion of people with S20 camera problems. No joy.
The crack about NFC seemed weird. I had never used NFC (e.g., payment by holding phone or another device close to another sensor) until recently. I went to Settings / Connections and turned off NFC, and shazam! The bank app at last took and used a picture of a check without a fuss.
I won't say I was intrigued, but I was curious enough to turn NFC back on and to take my NFC-ready credit card out of my phone case: again I was able to take the picture successfully. I would be happy if this had not been such a grand waste of time.
And that's just one of the things that has bugged me about this phone.
I hope that my account relieves another sufferer.