Hi, welcome.
What grid code are you using?
Do you have any automations or assistants loaded?
Do you use any energy/grid meters?
Outside of automations, the decision to connect or disconnect is controlled by the multi and grid code. Very little change has happened to affect this.
The GX doesn’t usually play a part with this - have you tried to disconnect the vebus cable from the GX when you experience the issue?
Does choosing redetect from the GX multiplus menu help?
As a new member, just a reminder to brush up on our guidelines to set the correct expectation: