I tried to close GSX but I do not succeed. I tried to unload and reload coatl. Finally I have to restart MSFS
Please clarify what do you mean with "I do not succeed". In general, ANY problem that cannot be solved by restarting Couatl, it's NOT caused by GSX. If the only way to fix your problem was to restart MSFS, the problem wasn't GSX and, instead, it was likely having hit the maximum Simobjects limit, which breaks up Simconnect (which GSX depends on), until a restart.
Have a look at the Troubleshooting chapter of the manual, starting at Page 94, which discussed the reasons of the Simobject limit and some solutions.