Very strange. I would report this to the Eset people and to Microsoft via the feedback hub. I have never once had an icon that I turn on in the dialog I referenced be pushed into the overflow area. Its very reason for being is to prevent that, so something's amiss in this case.
Of course, I only keep 6 really essential bits constantly showing in the main system tray. Anything else I let get pushed into the overflow area and get to it in there on the odd occasion I want to check it.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore