That was the same bug that was in that game scene/mine last year.
Have you tried completely shutting down your game & restarting it..... fully closing down not just swiping it into the background.
Clear your cache, cookies, history, etc.
If you have you player ID number & game progress registered with either your email address or Facebook account.....try uninstalling & reinstalling.
If none of these suggestions work for you....then i suggest that you contact Pixel support directly.
You can contact Pixel support directly through your game settings menu
Alternatively you can contact Pixel support directly via this link
Do not type in the white search box ... go to the categories written in blue.
Remember to check your spam / junk folder for replies.
Do not send multiple Pixel Support tickets in quick succession or their spambot could eat them.
You can check out the relevant Wiki pages, quests, maps, videos, guides, walkthroughs & hidden gifts/bonuses