If you’re using the category widget in the Widget Pack you should disable the category drop down in Tile Plus. They use separate methods to query which category to display which are incompatible and would likely be confusing to your users. The category widgets uses permalinks to goes to a specific category page while the drop down in the template will do a query to filter the results by the selected category. I do have plans on implementing logic where if a category permalink is used, it’ll override and set the category filter. This will provide a more seamless experience.
However, with that said… there does seem to be a bug that I’ve confirmed just now. What is happening is every category in the drop down is being marked as the selected category which would result in the last category in the list being shown as the selected category. What should occur, presently, is the category drop down should be unaffected by the permalinks. I’ll track down the issue and get that fixed for the next release due out soon.
Apologies for the trouble!