WD My Cloud Home

I’m not a technical person, so please bear with me.
I’d been storing my Scrivener projects on an WD external drive connected to the home network for years. When using this device, I didn’t need to be connected to the internet and I could work from either computer. The drive worked great for about 10 years and just last month it started crashing and making funny noises. I knew I had to transfer my work quickly before it died. So my hubby bought me a WD My Cloud Home 4TB. I transferred my WIP which I’ve been working on for about nine years to this device. The first few times I worked off this drive was fine, but now, every time I try to close the file, my computer starts beach balling and it takes a couple of minutes to save and close. Also, when I opened it with my old Macbook Air, it was fine the first few times and then it started crashing so I’m not using it anymore for fear of ruining something.
Can anyone help?

The obvious cause is slow wiFi or poor WD software implementation of the drive as a personal cloud service. It could be something else, but I doubt Scrivener is the culprit.