I have just tried to download the beta using the beta install string and I have downloaded v 1.49.5-199. Have I not left it long enough or do I need to do some thing special to get this?
That build would be a special test-branch just for this problem so it would not be showing up in any normal installation script if that is what you are talking about. You will have to do a manual install for this one (really it's only replacing the .exe that is required)
If we can confirm the fix solves the issue then it will typically be integrated into the "proper" beta branch and then go on to be part of stable rclone in the next release.
Installed the beta version and running a sync, so far it has been running for almost 19min and hasn't bombed out yet, which is better. I will confirm once the sync finishes with no errors.