All stuff that you claimed (was placed before withhin a new claimed area) will have a shortent decay timer, its 2 days for floors and pillars.
So when you dont reset daily it might vanish. You can rebuild after you claimed to prevent that.
The devs came and said new claim system, better then the old (2019). Turned out they implemented a mess, super buggy and exploitable.
Why everyone start to reinventing the wheel first tries a rock?