Help! The cracks

[Madisonsha]

Hi, recently moved into our new house built in 1985...noticed few cracks on walls and in window frames. Used decorative gaps filler, after 2 months noticed gaps in the window frames. Any suggestions? Please check photo and this is the 3rd

Any cracks elsewhere? Is there flexible sealant where the cracks are...ie silicone of a good quality?

@MarieG10 I have not applied this not yet. I did other 2 rooms i could see a gap and used the same filler for skirting looks perfect now. Not sure how to fix the window gap