[SOLVED] Major problem with panels

This is a problem that has just started without any obvious changes.
When either left or right panel is closed everything (buttons in bottom navbar etc) becomes non-responsive and have to kill app and reload to get anything to work.
Was problem with F7 3.4.0 and updating to 3.4.2 has not solved it…
Any ideas to overcome this will be much appreciated.

Tried F7 JS from 3.3.0, 3.3.1, 3.3.2, 3.4.0 and 3.4.2 and all have the panel issue…

Tried a number of changes to try to track down this issue - solved by replacing the generic app.js I was using with another one (I copied from one of the F7 template apps). The new one is largely the same although smaller but, clearly, has a significant difference or omission!!