Access Insert Query only inserts halfway of the items to linked Sharepoint List

[Juliatoute]

Hi! I really need some help
I have an Access database with 2 tables. In table A I have my data being uptaded from an Excel file with VBA. This Works fine.
Table B is a Sharepoint list, linked to access. It is identical in structure as table A (except for the automatically created columns Sharepoint has, like Created date, ID, etc.).
Everyday I perform a delete from * query in Table B and then insert all items from Table A to table B. This was a workaround to get items from Excel to Sharepoint since I did not find an easier way.
This worked fine for 2 months. Suddenly it started giving me an error after I run the INSERT Query "Cannot update. Database or object is read-only."
It confuses me because it does insert part of the records correctly and then just stops halfway through (more like 20% through).
I've checked everything I could find on this error message and couldnt find the problem. Caching, permissions, I even created another list and tried to start over and I still have the same issue.

[#2]

@Juliatoute 

Typically, when a procedure has worked properly for some time, but then stops working, the first thing I look at is the data. Something in this batch of data no longer conforms to the original expectations set up to handle the import of the data. The fact that it still imports some portion of the data, but then stops also adds to that suspicion.

Look at your data.