Hi, best is to send the "Bugged" save directly to the SE Programmers in a new Bug report created on the Official SE1 Support Portal, they will test it and tell you if it is a new Bug they will fix or not.

Question first :
-> Is it the same in brand new created no Mods world on default settings or it happens in only one specific save ?

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IF bugged in the new created world
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Click "Submit Bug" on their Support Portal :

https://support.keenswh.com/spaceengineers/pc
(create "Bug report" or "Request help"(Private) or "Feedback"(Petition) on the Portal)

I will add :

You may share your "Bugged" save here, me and players will be able to load to help you find the cause.

-> How to share a world save on the Workshop :

1 - Select your save.

2 - Click the "Publish" button on the left.

3 - Choose a proper Tag, check Steam upload and click the OK button.

4 - Your world will be uploaded to Steam Workshop.

5 - Paste the Workshop item link here.