P: Grouped smart objects become too large when saved

Photoshop 25.7.0
Windows 10

Since some versions of Photoshop there has been a rather annoying problem that costs a lot of storage space and often exceeds the storage size of PSD files. Grouped smart objects become too large without recalculation!

The simplest case in which the error occurs for me is as follows:

1. I open from ACR  3* RAW files from a Sony camera as smart objects in Photoshop and arrange them as  layers in one image.
2. When I save this image with 3 layers it is 1.47GB in size
3. If I group/create and save these 3 smart object layers as a new smart object, it can only be saved as a psb file and is 2.3GB in size.
4. However, if I now open the smart object grouping once and open a smart object in it again in ACR and have it recalculated without any changes by closing it, I can then also put it back into the grouped smart object with a recalculation without any changes. When I save this image again it is only 1.77 GB in size.

So the problem is this: When smart objects are grouped into a new smart object, the image becomes far too large when saved. If you trigger a recalculation of the grouped smart object, for example by recalculating an inner smart object, it will become smaller again.

The problem also occurs when an inner smart object is just deleted. The problem can be reproduced at any time and has occurred since several older versions of Photoshop.

I would be very happy if this annoying problem could be solved.