ERROR: HTTP ERROR 500 After Roundcube Login (2)

After an Ubuntu update it seems the Roundcube of my MiaB is broken.

I checked the Nginx error log and it’s giving me back this:

2020/06/12 13:41:23 [error] 13933#13933: *87 FastCGI sent in stderr: "PHP message: PHP 
Warning:  session_start(): Failed to read session data: user (path: /var/lib/php/sessions) in 
/usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_session.php on line 136
PHP message: PHP Fatal error:  Uncaught Error: Undefined class constant 
'MYSQL_ATTR_FOUND_ROWS' in 
/usr/local/lib/roundcubemail/program/lib/Roundcube/db/mysql.php:149
Stack trace:
#0 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php(152): rcube_db_mysql- 
>dsn_options(Array)
#1 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php(138): rcube_db- 
>conn_create(Array)
#2 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php(230): rcube_db- 
>dsn_connect(Array, 'w')
 #3 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php(416): 
rcube_db>db_connect('w', true)
#4 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php(379): rcube_db- 
>_query('SELECT `vars`, ...', 0, 0, Array)
#5 /usr/local/lib/roundcubemail/program/lib/Roundcube/session/db.php(106): rcube_db- 
>query('SELECT `vars`, ...', 'ivkv3u83phrc05p...')
#6 [internal function]: rcube_session_db->read('ivkv3u83phrc05p...')
#7 /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_session.php(136): session_sta" while 
reading response header from upstream, client: 256.256.256.256, server: box.domain.tld, request: 
"GET /mail/ HTTP/2.0", upstream: "fastcgi://unix:/var/run/php/php7.2-fpm.sock:", host: 
"box.domain.tld"

I already tried uncommenting the /usr/local/lib/roundcubemail/program/lib/Roundcube/db/mysql.php:149 rule but that doesn’t seem to work so before breaking more I brought that back in old state.

Does anyone have an idea what to do to make my Roundcube visible again?

P.s. I am already on 0.46.