Sudden appearance of crack and warping on drop down ceiling in Kitchen combined with random sounds

This is a house that was built in 1967. We bought this home in end of 2020. In December of 2020 when we moved in, we had popcorn ceiling removed and replaced some areas of bad sheetrock. We had the whole ceiling repainted. A portion of our kitchen and entry way has drop down ceiling. There were no cracks or any visible warping until a month or so ago. All of a sudden, a big crack started to appear (shown in pics). We thought it to be due to normal wear and tear, but it seems to be getting worse at a very rapid rate. Initially it was a partially visible crack but now one side of the crack feels lower than the other side. When I run my finger along the crack, I can clearly feel the difference in heights between either side of the crack.

Upon further inspection, we started to notice some warping or unsettling in other areas of drop down ceiling. When I say warping, it looks like the location at which two pieces of sheetrock are attached is sinking down. I am not sure if it was there from the beginning (and we didn't notice) or if it is new. Any idea if this is a serious issue? Could this be caused due to settling of foundation? We did have an extremely wet winter this year. I do not notice any visible cracking on the foundation anywhere around the house. Who should I call to diagnose this issue?

Crack - https://imgur.com/6bAH9RL
Close up of crack - https://imgur.com/FeYYQ7v
Wider view of crack - https://imgur.com/VEo3WCJ
Warping Location 1 - https://imgur.com/1o9sfLU
Warping Location 2 - https://imgur.com/STpnMs2

In addition, we hear a random sound once every few hours. It sounds like a twig breaking or a heavy metal piece falling on the floor. It comes from somewhere in the attic but never from the same location. It is super hard to identify exactly where it is coming from. Now I am worried if something is going to collapse. This sound is very random and we hear it once every few hours, may be about 10 times in 24 hours. I recorded the sounds using a security camera over couple of nights and combined all of them into one. The camera remained at the same location. The loudness and type of sound varies for each one which indicates that its coming from different locations.

Sounds - https://youtu.be/UvOgTJAhEhw

I am really scared this could be a major issue. I am not even sure who to call to diagnose this. Any ideas or suggestions are highly appreciated.

Thanks.