Contact the board vendor for assistance. CONTROL works with any board that runs stock standard Grbl 1.1 from Grbl v1.1 · gnea/grbl Wiki - it does not support other forks and 3rd party firmwares - only official Grbl.
I received a new Phoenix controller about a month ago. I had some connection issues (actually the exact same as here) that was solved by a simple driver update through the troubleshooting link. I haven't touched anything from then to now. The problem is back. Neither of the three computers that I used before are working. The only connected wires are the VCC (24v), GND, and the USB, so a miss wire is not a factor. The only thing that changed was an auto update with Openbuilds Control (1.0.330). I have tried reinstalling. There are no new updated drivers available. I don't know.
@Peter Van Der Walt I did reach out to Phoenix and am waiting on a response. The board is on GRBL 1.1.