K-9 switches to full-screen mode when selecting an embedded link in a message

First-time poster here; please forgive any faux pas, as they are unintentional.

I’m using K-9 on a Lenovo Tab P12 Pro (TB-Q706F), recently upgraded from Android 11 to 12 (Kernel 4.19.157-perf+ / #1 2022.08.25 07:14). Before this upgrade, K-9 behaved itself very well when run in a less-than-full-screen window. I could click on a link in an incoming message and it would open that link in my default browser (Opera); K-9 would remain in its less-than-full-screen window.

Since Lenovo upgraded the tablet to Android 12, when I click on any link in an incoming message in K-9, Opera is properly opened (as a window), but K-9 shifts to full-screen.

I’ve verified that this behavior also happens when I switch my default browser to Chrome: Chrome opens properly in a window, but K-9 shifts from windowed to full-screen.

Curiously, I don’t see this behavior if I set my default browser to Firefox. Firefox opens properly and K-9 remains in windowed mode, which is what I want.

Anyone else seeing this? Suggestions?

Thank you in advance.

I’m not able to reproduce this using an emulator with freeform windows. Maybe this is a bug in Lenovo’s Android version?