Massive drop in framerate for Intel Arc Graphics

With Zwift Version 1.56.0 I get a massive drop in Fps for Intel Arc Graphics.
Running an PC with Intel ARC 770 it is now down from 60Fps in 4K Ultra profile a year ago to below 20 FPS,
even if barely any other rider is around.
Using an Laptop with both integrated Intel Iris XE Graphics and dedicated Intel Arc A370M Graphics -
Fps for Arc A370M is roughly half the value compared to Iris XE with the same profile and graphic settings.
Intel customer support states: “After thoroughly checking the system, it is not their fault. It looks as if Arc graphics are not supported by Zwift.
Everything is fine from our side”

And it seems it looks this way. All other games and things are running very well with Intel Arc.
Not the slightest glitch.
This would render Intel Arc graphics for Zwift’s current game version as not suitable.

The low fps value is nearly independed of any change in graphics setting, having riders around you or standing alone besides the road.
Like something is blocked or having a deadlock.

I don’t think the fps issue surfaced wit 1.56.0. If I remember right Zwift had a major software revamp same month ago.
This could be the starting point. Zwiftalizer 2.0 stores all the uploaded logfiles for eternity. Searching there for logs with Intel Arc GPUs
could reveal something more.

Does anyone else experience this?

For checking fps:
Navigate to C:\Program Files (x86)\Zwift\data\configs and add the following line
set gShowFPS=1
to your profile file basic.txt, medium.txt, high.txt or ultra.txt
Zwift shows the fps value in the left upper corner of the screen afterwards.

For setting the Graphics unit:
For those having a dedicated graphic they have probably an integrated GPU too.
In Windows 11 you can explicitly set the graphic unit for each game.
Settings=>System=>Display=>Graphics:
Custom Options for apps: Add Zwift to list by browsing to and adding ‘C:\Program Files (x86)\Zwift\ZwiftApp.exe’
After it appears in the list select options for it to select the GPU. ‘Power Saving’ for integrated GPU or ‘High Performance’ for dedicated one.