Control panel sidebar disappeared!

[Leonardo Fiori]

As you can see from the image my sidebar disappeared.

On RT AX88U
Merlin 384.11_2

Moreover it randomly disconnects from my 4g modem attached to the wan port.. but thats another problem

 

[AndreiV]

Basic housekeeping , first clear your browser cache ( or use a different browser) then power cycle your router .
[Leave power button on, pull mains cord from the socket, leave router alone for 2-3 minutes then power up again.]