I have had been unable to clip to Evernote on my Android phone for a long time, I think since they did their software revamp, with the symptoms you describe - the Notebook field flickers with "Loading", and if you hit Save, it says "Error Clipping". This has been through multiple versions of Android and Evernote on two different Google Pixel phones - a 4a-5g, and a 7 Pro. I sent a support ticket in, and they expressed sympathy but gave no timeline for a fix.