I recently upgraded to the Mystic Spyglass and traveled to the Forest Gauntlet. Upon using the spyglass, the view of my character became stuck in the spyglass mode no matter what I did. I tried selecting other tools, reselecting and viewing/zooming through the spyglass, using the glider, and fighting but could not get it to go away. This did occur after a reload that was forced by a "travel error" so I'm not sure if it is related. Exiting to the main menu and reloading the character solved the issue.
Also happened to me but in Swamp Gauntlet
So I was able to recreate it in abeyance and i think i figured it out. Basically don't use the Spyglass as soon as yo load into any realm. Seems that is what messes up the game for some reason. I will explain what i did, travelled back to the gloom desert, jumped on some high ground in the area and used the spyglass. It worked as normal, tried multiple times just in case. Travelled back to Abeyance, and instantly used it and it happened first try.
Just had this happened to me too. Location does not seem to matter since i was in Gloom desert. Still able to do everything else normally. Travelled back to abeyance and able to use the spyglass normally there.