[Varstahl]

I'm not sure how much it pertains to the post above but I get what looks like full HD, and surround on Win 10 Pro.  I just rented a movie, and watched it and it was about bluray quality.

Surround? Yes. HD quality? Nah. Of course there are some exceptions, I'm mostly talking about the encryption used on PrimeVideo.com for the majority of users. There are/might be titles or conditions under which HD or FHD is possible, I just don't know of any.

Where is this option available? From the context menu? In the add-on settings? Last night my watchlist was suddenly empty and I looked for this option to try and refresh, but could not find it. I ended up doing a search for the show I wanted to watch and had to play the episodes from the search results.

Contextual menu. Right click or contextual menu keypress on the item you want to refresh. Works with remote too if there's a button configured for that.

Code:

We've made a few changes
Categories for familiar areas of interest. Your Video Library and Watchlist are now found in My Stuff.

Not sure, but perhaps this explains the now empty watchlist?

It's possible, I don't know of anything breaking yet.