Bingo.
Look if only one php version is installed with this command:
dpkg -l | awk '/^ii.*php/ {print $2}'
Is it only 8.2 or are there some older php versions somewhere not yet deinstalled?
Look what php is used by your apache webserver with this command:
apachectl -tD DUMP_INCLUDES | sed -n '/php.*conf/ s#.*/\([^/]*\)\.conf#\1#p'
Is there only one or multiple lines and does it match? Is it 8.2 as well?
If not, fix that first.
Aditionaly look here: Upgrade PHP 8.0 to 8.2 - #2 by ernolf
Hope that helps,
much luck!