I'm a newish player and was going through the story very, very slowly. That meant that I was stuck with a full XP bar for a long time until I had enough to unlock Advanced Logistics. At some point I became unable to select different mastery tracks (I still have 2 masteries to unlock under Legendary Crafting and 1 under Fractal Attunement ).
Last week I finally unlocked Advanced Logistics, but didn't play much after that. Yesterday I decided to finish LWS2. I got some mastery points from the story, but noticed that my XP bar wasn't moving and when I place my mouse pointer over it, it states 0 XP. I did at least 2 chapters and the bar didn't move. I also noticed that no mastery track was selected and nothing I did made the check mark appear (left click, double left click, right click, double right click, clicking on the text... I clicked everywhere I could think of).
I uninstalled and reinstalled the game last night and nothing changed. I noticed I got a spirit shard after completing a city map, but the XP bar remained empty, stating 0 XP. No mastery points were gained.