2 of my Blizzard Mountain Achievements have not been earned on Forza Horizon 3.

Hi there I wonder if anyone can help me is there away of getting 2 of the Blizzard Mountain Achievements to activate without starting the whole game again the 2 achievements that have not activated are Winter Wonderland & Still Never Found That Yeti even though if you look ion my Blizzard Mountain progress stats I have found all 50 roads & all 5 Beauty Spots.That is why I hate the fact you have to be online to earn Achievements so if the game glitches & Achievements dont get earned then you can still earn them offline by restarting the game again getting the 2 Achievements then deleting the save game file you used then going back online & redownload the cloud file to your system they really need to patch that so you can earn Achievements offline as well.