Save changes in Haproxy causing Crash report

[wickeren]

For some unknown reason to me, I can not make anymore changes in Haproxy, gettings this crash report:

[30-Nov-2021 09:15:13 Europe/Amsterdam] PHP Warning:  Unknown: Input variables exceeded 5000. To increase the limit change max_input_vars in php.ini. in Unknown on line 0
[30-Nov-2021 09:15:13 Europe/Amsterdam] PHP Warning:  Cannot modify header information - headers already sent in /usr/local/www/guiconfig.inc on line 30
[30-Nov-2021 09:15:13 Europe/Amsterdam] PHP Warning:  session_start(): Cannot start session when headers already sent in /etc/inc/phpsessionmanager.inc on line 41
[30-Nov-2021 09:15:13 Europe/Amsterdam] PHP Warning:  Cannot modify header information - headers already sent in /usr/local/www/csrf_error.php on line 22
[30-Nov-2021 09:15:14 Europe/Amsterdam] PHP Warning:  session_start(): Cannot start session when headers already sent in /etc/inc/phpsessionmanager.inc on line 41
[30-Nov-2021 09:15:14 Europe/Amsterdam] PHP Warning:  Cannot modify header information - headers already sent in /usr/local/www/csrf/csrf-magic.php on line 234

Running haproxy-devel 0.62_4 on latest 2.6.0 snapshot (for some Ipsec reasons)
Any ideas? Don't know if this is a package issue or a general Pfsense issue.