A further check of the property management company revealed nothing other than It is now the home of Hartford's USL Championship club, Hartford Athletic. The various teams probably bring their own radios with them while at the stadium, if they even use them! And there is always the chance they are encrypted-pro and semi pro teams don’t want to be overheard. As for the facility itself, as Reconrider has posted, close call is probably your best bet, but I wouldn’t be surprised if they also use some sort of encryption or proprietary trunking. Doing an FCC search on the property management company might help.
If you do happen to identify comms, submit them to RR.