Cannot remove brake pads (Magura MT5)

Info:

• Magura MT5 double pistons
• Magura 9P brake pads (they don’t use retaining screws)
• Brakes and pads are 50km old (new bike)
• Only ridden in city with dry weather conditions
• Pics are of the rear brake
• After adding a 40° hose outputs to both masters, I got ready for a brake tiny refill and bleed (oil is lost when changing master outputs).

Problem:

I cannot manage to remove the pads since the right side pistons are not all the way in, compared to the left side, where they are almost all the way in (I think they don’t push any further. The little "L" shaped hooks on the pads are blocked by the right pistons not fully pushed back.

What I tried:

• I inserted pad spacers (the yellow Magura Transport Device) between the pads but the right pistons stayed in place.
• I opened the master bleed screw (EBT screw) thinking the system may be overfilled (even though I lost some oil), still no change.

I don’t think the pistons are stuck because the brakes worked wonderfully and they are only 50km old and only rode in dry city conditions. They seem very clean and functional.

Any help is appreciated!