Sessionwire is a professional audio platform, and it's only as good as the connection under it. Running a Session over Wi-Fi is like plugging a vintage U47 into a vintage 1073 through a $200 wireless unit instead of a good XLR cable. Everything else in the chain is great, and the weakest link decides what you hear.

Connect every computer in the Session to its router with an ethernet cable, and turn Wi-Fi off on that computer while you work.
"I've got plenty of speed" is something we hear a lot, and it's almost never the problem. A Session uses only a few megabits per second. What matters is that every packet of audio and video arrives, and arrives on time.
Wi-Fi is bad at exactly that. It loses packets to all sorts of things:
Mesh systems and the newest Wi-Fi standards don't fix this. Interference is still interference.
Sessionwire is built for low delay and unprocessed HQ Audio, so it keeps buffering to a minimum. That's what makes a remote Session feel like you're in the room, and it's also why a lost packet is something you hear rather than something hidden.
Sessionwire lowers video quality first to keep HQ Audio steady, so blurry or frozen video is often the first warning.
Ask the people you work with to plug in too. A Session is only as steady as the weakest connection in it.
Run the Network Test in your Studio to check your network isn't blocking Sessionwire. See Run the Network Test. If your internet provider recently changed something, ask them whether they've turned on any new security features, which can block the connections Sessionwire uses.