Hey Guys, I just found a fix for this as i’ve had this problem for a while (the fix makes absolutely no sense but it worked).
Once you have opened the bridge plugin within UE and the Quixel bridge window has appeared. Change the path from the C drive to the D drive in the preferences.
If you have no D drive, get an external hard drive and change the path to a folder on that drive (that’s what I did) and it will hopefully fix this issue.
It didn’t work at first when I tried it, but keep switching paths and attempt to login after each path change and hopefully it will work as it did for me! Again, I have absolutely no idea why that works but it did!