Update 103 and 105 developer..the issue is still not fixed...anyway thought to share this
This is the autoit code I wrote 2/3 months ago (since the issue started) to push the mouse back in position it is still working great

#include <Misc.au3>
#include <AutoItConstants.au3>
#include <Process.au3>

Global $Paused
HotKeySet("{DEL}", "Stop")

Run("launcher.exe")
ProcessWait("opera.exe")

While ProcessExists("opera.exe")

  Local $limitAccess = WinGetProcess("[ACTIVE]", "")
  Local $limitName = _ProcessGetName($limitAccess)

      if $limitName == "opera.exe" Then

        $mousepos=mousegetpos()

          If $mousepos[0] >= @DesktopWidth-3 Then
          MouseMove(@DesktopWidth-3,$mousepos[1])
          EndIf
      EndIf

  Sleep(50)

WEnd

ProcessWaitClose("opera.exe")
Exit

Func Stop() 
Exit
EndFunc   

I just love the design so I didn't want to go back to older versions so. I came up with a personal solution 2/3 months ago since I saw the issue...
The trick is simple...
If you can code in python or other macros creating software just lock or return the mouse to screen position, add a condition where this only applies to opera.

You can also try my compiled code my google drive
Just extract the 2 files to your opera installation folder cause the software will look for the opera launcher exe
Then link the shortcut to start or taskbar then run

Update 103 and 105 developer..the issue is still not fixed...anyway thought to share this
This is the autoit code I wrote 2/3 months ago (since the issue started) to push the mouse back in position it is still working great

#include <Misc.au3>
#include <AutoItConstants.au3>
#include <Process.au3>

Global $Paused
HotKeySet("{DEL}", "Stop")

Run("launcher.exe")
ProcessWait("opera.exe")

While ProcessExists("opera.exe")

  Local $limitAccess = WinGetProcess("[ACTIVE]", "")
  Local $limitName = _ProcessGetName($limitAccess)

      if $limitName == "opera.exe" Then

        $mousepos=mousegetpos()

          If $mousepos[0] >= @DesktopWidth-3 Then
          MouseMove(@DesktopWidth-3,$mousepos[1])
          EndIf
      EndIf

  Sleep(50)

WEnd

ProcessWaitClose("opera.exe")
Exit

Func Stop() 
Exit
EndFunc   

I just love the design so I didn't want to go back to older versions so. I came up with a personal solution 2/3 months ago since I saw the issue...
The trick is simple...
If you can code in python or other macros creating software just lock or return the mouse to screen position, add a condition where this only applies to opera.

You can also try my compiled code my google drive
Just extract the 2 files to your opera installation folder cause the software will look for the opera launcher exe
Then link the shortcut to start or taskbar then run