@gillygilly answer for what.. He never provided any sort of details.. Can you lock yourself of the gui - sure you can.. But it takes effort..
There is an anti-lockout rule by default on pfsense lan.. Any rule you put on the lan wouldn't matter because the ant-lock out is at the top. And way up top in the rule order
[23.09.1-RELEASE][admin@sg4860.home.arpa]/root: cat /tmp/rules
# make sure the user cannot lock himself out of the webConfigurator or SSH
pass in quick on igb0 proto tcp from any to (igb0) port { 8443 22 } ridentifier 10001 keep state label "anti-lockout rule"
So even putting rule in floating wouldn't block you..
But sure you can still shoot yourself in the foot if you try.. So a gun in a locked box with no bullets is kind of hard to shoot yourself with..
So you would of have to unlocked the box, then gone and gotten bullets.. Ie disable the anti-lockout and created some rule that blocked you.. Off the top of my head not sure what sort of feed/rule in pfblocker would do that? I am not aware of any rules would block rfc1918 space? Maybe there are?
But for all we know this user was trying to access via some fqdn that pointed to his pfsense IP, and that wasn't working with pfblocker enabled and figured this was locked out?
Did he go in after he removed pfblocker to see what rule was trigged to lock prevent his access to the webgui?
If you find yourself locked out - consult
https://docs.netgate.com/pfsense/en/latest/troubleshooting/locked-out.html