klaeuser The setting for the AOSP keyboard to display the on-screen keyboard while a physical keyboard is attached disappeared with Android 15. It's really annoying. If you enabled the setting before upgrading from Android 14 to 15 the setting will still be enabled. That's why I only noticed this when I made a new profile and attempted to use my Token2 key in that profile. I haven't found a way around it, other than using Gboard, which has this option within its app settings. Perhaps other third-party keyboard apps have it as an option as well. If you find a keyboard app that has the option but still want to use the AOSP keyboard as your default keyboard, you could install the keyboard app, enable the option, then select the globe icon that appears in the bottom-right corner when you need to input your PIN.
I asked Token2 support about this and they replied with
The keys incorporate a HOTP applet which operates by sending the generated OTP through HID emulation. Consequently, this device is automatically recognized as a keyboard. To circumvent this, we recommend either disabling the OTP functionality of your security key using our Windows companion app or unplugging the key while entering your PIN code.
The latter doesn't actually work, as when you reinsert the key you need to grant Play services access to it again, and you have to reenter the PIN. The solution of disabling OTP functionality is okay if you don't use that feature, but it's a silly workaround, especially if you don't use Windows. I just use a different keyboard app.