Unwanted "Panel" Keeps Appearing (automatically) ? How To Disable This Action ?

[Robert11]

Hello,'

Thanks for all the previous help.
Will blame my ignorance on "old age" now.

Running W10

Every few minutes, a 1/2 width panel appears.

It has "recently added" at the top
And all my Folders on the left, shown vertically..
A bunch of APP icons on the right.

Not sure what it is called.

Driving me crazy.

A simple click on it makes it disappear, but in a few minutes
it pops up again.

How, please, can I get it to never appear (automatically) by itself ?

Thanks,
Bob