Wild question: Barrier being the cause to translucent windows on Mac OS?

[hiuwo]

I am sorry to ask an unfounded question,
but I have been using synergy, then barrier for many years, and since maybe 3-4 years ago, my iMac started sometimes have its windows go translucent and I dont know why.

--------------BACKGROUND---------------------
Server: Microsoft Windows 10, barrier 2.4
Client: Mac OS Monterey 12.4, barrier 2.4

My hot key to move from windows to mac is F22,
and on mac screen settings I swapped modifier keys for between Ctrl and Super (because of usage preference to minimise shortcut keys confusion).

I have set a key on my windows computer to have a macro to go:

1. F22 (move cursor to mac)
2. LCtrl+Tab (to swap to last open app as it functions as Cmd+Tab)
3. LCtrl+Tab (to swap back to the original app, as to workaround the issue outlined here:
   Barrier in conjunction with "Automatically hide and show the menu bar" on Mac doesn't work reliably #675)

--------------ISSUE----------------------------
Back to the topic, I am not entirely sure if the issue is due to barrier, but occasionally (like once every month on average. sometimes once a week) when I click the macro, it will turn some windows translucent.. (see picture below)

Now I had installed SIMBL before like using Afloat, but I am pretty sure I uninstalled it.
It maybe a conjoint buggy effort of F22 cmd tab and movement being pressed or some hidden app shortcut being pressed, but having no actual clue, I wonder if anyone has any clues what causes this? Or replicate this? cuz built-in translucent mac windows are pretty fascinating. It is quite frustrating right now as there is no way to correct the individual windows (one app can one solid window one translucent window), and requiring a relaunch or a restart.