Update 8.0 GPS now wrong

I updated to 8.0 and since then distances I've been covering for 18 months are coming up wrong. A 1.06 mi track on both my Fenix 3 and 5S until the update has come in at 0.87 and 0.91. It also happened with a 1.66 miler. After update it dropped to 1.44 miles. Any suggestions.