Hi, I also have the same problems but only since the new SU3 1.5.4.0 Beta of the SIM.
I rolled back to the SU2 version to back check if the problem still exists there but in SU2 this appears not.
I also have to say that since 1.5.4.0 not only the MFD and OIS are flashing when you switch back from external to cockpit-view the whole cockpit is flashing, all button-lights are on and no button registers any input while that happens - also all button highlights from the sim are flashing on the buttons as well.
I also noticed that the lighting on the surface of the cockpit textures also is off like its not corresponding to the actual "sim-lighting".
After a few seconds the flashing stops the surface textures of the cockpit are back to normal and all is functioning like it should.
Looks like they changed something with the lighting in the sim with the new beta and thats why this happens?
I assume that because the problem with invisible engine spinners and blades in certain lights is fixed in the lates Beta build.
If you want to see what I mean the guy from this topic has mentioned a similar problem but his screenshots show exactly what i mean with textures while the "flashing" occurs:
EDIT: I tryed a bit this evening and found out that ist must be related to some type of changed LOD settings/curves they added with the last SU3 update.
When you go in dev mode and activate "Use new LOD Curve" it gots even worse, the whole cockpit then looks like strait from MSFS2004 with almost no Antialiasing no reflections, no texts, no marks.
Maybe the changes in LOD have to be adapted to the A350?
I attached pictures for clarification:
normal behaviour on SU3 1.5.4.0 with "old LOD Curve" after switching from external view to cockpit:
this usually takes a few seconds the lighting and all goes back to normal: