Try a soft reboot by turning the phone off and on @Knightrider41
If no joy then To see if it's an app causing this I'd suggest to put the phone in Safe Mode which disables your downloaded apps and leaves the stock ones working which can help you determine if this is a non stock app.
If it continues in Safe Mode then come out of safe mode and try the Samsung Beta keyboard or another 3rd party one to see if things improve and check there's no pending updates for your keyboard.
Ultimately a Samsung Experience Store or a Samsung Service Centre can help via a diagnostic
Current Phone ~
Samsung Note 20 Ultra 5G SM-9820 _256Gb SnapDragon 865+
Samsung One Ui 2.5/ Android 10.