In that case it sounds like you are creating the objects as part of a 'group'.
Unlike Blocks it is possible to add or remove geometry from a group as you are working.
https://cadsetterout.com/autocad-tut...to-use-groups/
You can change whether grouped objects can be selected individually or only selected as the whole group:
https://knowledge.autodesk.com/suppo...C2D21-htm.html
Groups can also be 'Exploded' to make the grouped items individual again.
If you are not using the group command yourself but it is being turned on automatically then you might want to look at why that is happening.
(If you use any lisps then a lisp could be turning it on but not off again).
Im intelligent enough to know that I dont know everything; but I'll tell you all about it anyway.