ᐅ Different Support Types for Window Lintels

We are planning to build a house with relatively large windows (floor-to-ceiling and up to about 4 m (13 feet) wide). A master mason explained to us that the supports for the window lintel on both sides should be made of the same material, as otherwise one-sided settlement and cracking in the plaster can occur. However, according to the plans, on one side there is solid masonry (17.5 cm (7 inches) calcium silicate brick) and on the other side a reinforced concrete column. Is this a design flaw, or is it acceptable to form the lintel supports in this way?

I think this is fine. Sand-lime brick and concrete have similar properties. Besides, applying an external thermal insulation composite system (ETICS) is required for this construction anyway. With the necessary reinforcement mesh, cracks in this area should not be a problem.