Too your question:
I think it is rather ironic, given the nature of this thread, that the image you posted above is not visible to us. It may be visible to you, but it isn't to us, as we are not logged in to the site the image is hosted on. That is one of the issues with using the cloud to host Cover Art images; you have to have access at all times.
and this is what I am doing, the local file is in the cloud.
All my files, business and personal are. NEVER an issues.
A local file is not a file in the cloud, because, well, it is in the cloud, and not on a local hard disk drive, or a network drive in your local network. It is only available over the internet.
This;
As I said, all available methods are tried. All work most of the time. None work 3% of the time.
then this;
All my files, business and personal are. NEVER an issues.
You say this doesn't work 3% of the time, and then claim you never have any issues with the cloud. You are having an issue with the cloud in regard to this problem!
Don't you understand that during the 3% of the time that the methods don't work, and none of them work, is because MC doesn't have access to the Cover Art image files which you have stored in the cloud? That is, if you are doing exactly what you are saying, and storing your Cover Art as images in a cloud service, accessed via the internet. Perhaps you aren't logged in to your cloud service when it doesn't work, or the service is just unavailable.
AS I said, I prefer to place the artwork in the cloud as it is the method that has shown the most consistency for success.
The most consistent and reliable method of storing and using Cover Art with audio files is to store them inside the audio file, in what is known as a "tag". Tags in audio and other files also store other metadata about the file; Artist, Album, Dates, Track name, etc.
Also, never ever delete an entire album and rip it anew just to add artwork via file. That is completely unnecessary and just a huge waste of time. The Cover Art issue can be fixed without doing that. Don't do it any more.
But enough of that. If you are willing to listen, and answer questions properly when asked, then we will be able to solve the problem. Over to you.