PT slows down when adding plugin shortcuts

[Raggi]

Hi.
I have lots of plugins and have been adding them to the plugin shortcut list (so you get them on the top of the plugin-list).Lets say I have about 8-10 plugins in both Stereo and mono list.
I'm not talking about the EQ and Comp option in preferences!

After a while pro-tools is behaving "laggy/slower" and doing a trash of prefs solves it. I have done this many times and last time was just before christmas.
By lag, I mean scrolling, drawing graphics.... generally it behaves slower.
The difference this last time is that I have not added the short-cuts and have not experienced any "slowness" since. Pro-tools behaves snappier.
I know the terms are wage.
I'm on Windows 10 and latest version of PT vanilla with a Avid approved HP Z machine.

Anyone else experience this?