This happens quite often and has for a while. Im curious if others experience this at all. Occasionally the WT list completely changes for me. As seen in the first two pictures it randomly became much shorter and the Kriminal WT's were completely missing. After I closed my DAW and reopened it, it was back to a full list.
In the second example (pictures 3 and 4), i had just used the mouse wheel scroll to switch between the Vintage Pulse and Vintage Saw WT (auditioning for a patch i was building). Following those two, I scrolled to Default. Now when going back to the drop down list to try both the Vintage Pulse and Vintage Saw again, both were missing from the list. Again i restart my DAW and they are back.