online thumbnails not updating

I have been using capture one for a few years. I keep all of my original images on an external drive connected to my iMac and my catalog is stored on a small, portable SSD. I take this SSD with me so I can edit offline images on my laptop. This has worked great for years. However, in the last month or so, the thumbnails of the offline images are not updating as I edit which is challenging. Any ideas on why this has stopped working?