I suggest disabling Use SSH-browser (graphical remote file browser in the sidebar)
and Automatically switch sidebar view to show the graphical SSH-browser
as suggested by the following Stack Overflow answer.
In newer versions of MobaXterm, these options were renamed to Enable graphical SSH-browser
and Automatically switch to SSH-browser tab after login
Under Settings, there are these 2 options that control this behavior that I typically turn off.
Source: