Meanwhile, we have uploaded the initial file you posted to the server again, and the md5 stayed the same. That is when we downloaded it from the server, it had the same hash than on the server and now after reuploading the same file to another product, it also has the same hash on the server again:
OP6 - HydrogenOS OB26-20190729134723.zip
So when someone downloads this file, it should also have md5sum of the above.
That means during our cycle with uploading a big file like yours the hash stayed consistent so far here local and on server.
We will keep an eye on the file if anything happens with it, like in case ot would change the md5sum in 1 hour or 24 hours.
If this stays stable, then we assume that the issue lies in uploading the file, since it seems to have ended on the server with a different hashsum than what you have local.
What browser or method do you use to upload the file?