pixel_player357598113
There was an announcement about this
https://forum.pixelfederation.com/diggysadventure/d/190661-known-bugs-issues-week-30
Number 4 in this link.
They suggest what to do there, I cite:
„ The issue is being currently further investigated. Also, when swiping the map further to the left, you should be able to find the locations needed for completing the quest. Last but not least, when completing a quest, you can also use the pickaxe icon in the quest log to enter the needed location.
Good luck and thank you for your patience in this matter 🙏“
Also you could contact support to let them know that this is still an issue
https://forum.pixelfederation.com/diggysadventure/d/190728-how-to-contact-pixel-support