So I finally finished that underwater level with four people and of course I find out I'm in the same boat as alot of others it seems. The achievement wont unlock :( I've tired looking it up online, but I only found things that people say "might" work. It also involves deleting my profile recovering and deleting my cache. Part of me wants too, but my other half doesn't want to chance losing all my progress on anything.
Basically I was wondering if anyone knows a confirmed fix or if deleting my cache will erase any of my progress. Thank you in advance :)