iPad storage, not full, says its full

Id like to begin this, by saying that 1) the disk actually has 70GB free space. 2) Do not reply with advice on how to clear space. 3) ..and I speak for everyone with this issue: I am talking about physical storage space on the device. I’m ****NOT **** saying I have 13KB left on my packed ipad, but since I bought some cloud space..g’doyyy!! That, was sarcasm. I’ve been getting an error message when saving projects, videos, etc, that “disk space is too full”. It’s a 128 GB ipad (2018). With 70GB free, what’s the prob?? Seems like lots of people have been having this issue, but answers are ALLLLLL about freeing disk space. I’ve literally deleted every video file on my computer, re-installed the iOS, with no success.