TL;DR: changing the name of the file anytime you change the contents should prevent this problem
Hello I created this topic to inform anyone that is having this problem about a possible solution.
In another thread, " Download Asset failed MD5 integrity check", pbpedro, the poster says that the problem is having spaces in the name of the file. However, I was having this problem without any spaces in my filenames, so I found another possible explanation, which is that the problem is caused by changing the contents of the files but keeping the names. I can’t be sure of this, but my theory is that the new file is being compared to the old MD5 hash, which is why changing the name of the file fixes the problem (there’s no longer an old MD5 hash to compare with). This theory is also consistent with the other post, as removing the spaces from the filename changes it.
Hope this helps.