library issue

I visit a fairly new library in SW MO, and use an older macbook air with OS X 10.15.7.

They have a 5 GHz and 2.4 Ghz wifi network.

I use the brave browser, and after about 5-10 minutes, whatever page I am on will hang, and nothing else will load.

As a workaround, I change networks. If I'm on the 2.4 one, I'll switch to the 5 GHz or vice versa. It'll work for another 5-10 minutes and reoccurs.

I suspect it's something with brave. I spoke with the IT director. Surprisingly, she has not heard of brave.

She asked for my IP address and checked something with filters she said, and was unable to see why it's happening, but she did mention a URL, which was an ad, and I suspect Brave's ad-blocking feature is not playing well with their network.

I asked what network hw they're using and she wouldn't tell me, for security reasons she said.

This has not happened anywhere else. Anyone know why this is happening, and any suggestions to give her?

Also, can someone recommend another browser that's as good better than Brave, aside from Tor, with as good or better ad-blocking and security?