With a Mocal sandwich plate, oil flow to the engine cannot be stopped.
The thermostat only restricts flow to the cooler, it does not restrict flow to the oil filter.
If the valve is jammed open oil will flow directly to the filter, by passing the cooler, then back to the engine. If it is jammed shut it will flow through the oil cooler first, then back to the engine via the oil filter.
In either scenario the oil returns via the oil filter.
The filter would be my first suspect in this situation.
Husam, did you change the filter when you swapped sandwich plates?
Just a bit concerned for you that the fix was a coincidence & it may happen again with catastrophic results.
Here is a link that explains how these sandwich plates work, it probably explains it a bit better than I do.
Cheers.
https://www.youtube.com/watch?v=l6Z2q-ttyOA