Have you verified that the item is still available, ships to your location, and that the offer is still valid (and no outstanding bids on the item if it is an auction listing)?
In similar situations I often suggest trying a different browser, though you have indicated you have tried on several different devices already. If you are using the same browser type or the same add-ons or extensions, a new, recent version browser with no extensions installed might be worth trying -- or else try using the eBay app.
When confronted with a progress ring that just keeps spinning, often the problem is that a particular handshake is not being completed successfully. This might be because an ad blocker, pop-up blocker or script blocker is preventing something from loading, or a possibly a security setting such as tracking protection is causing an issue. Try disabling those features to see if that allows your offer to progress any further.
I ran into a similar progress ring problem at checkout when I changed my browser's default behavior to open links in a new browser tab; the checkout was expecting the PayPal sign-in to be in a separate pop-up window, and opening in a new tab did not work for me. I had to check out in another browser until I restored the original default setting.
