Syther,
Are you using "ulx rcon say", or just "rcon say" in your V2 problem?
Please provide the exact error.
As for your v1.13 problem, has your 1.13 always done this?
Make sure you are exec'ing your banned files in your server (or listenserver).cfg
If you don't exec your banned_user.cfg file from your server.cfg, the previous bans you have aren't in memory to be written, or to deny access to those banned users.
I forget the exact names of the two files, but somewhere in your server.cfg file (or listenserver.cfg if a listen server), you have to have...
exec banned_user.cfg
exec banned_ip.cfg
(again, those two banned files might be wrong named)
I'll have to do more testing, but my apologies, I can't do it for another ~13 hours (work and dinner)