i ran a certified 1/2 marathon course and my Fenix 5x came I. .33 miles short. No problem as I adjusted the miles. But is doesn’t assign it as my new personal record? How can this be fixed anybody else have this?
Your expectations need recalibration. Programmatic checking for new personal records only happen:
on your Garmin wearable device (assuming it is a model that supports the feature, which is true for the f?nix?5X) upon completion and saving of a timed activity; and
upon upload/import of an activity record into Garmin Connect, if either the synced device advises one or more personal records was/were detected, or the total distance of an activity almost matches one of the predetermined distances exactly.
Why would any part of Garmin Connect automatically assign it as your new personal record, after you (as far as the system could know) arbitrarily edited the summary statistics of the activity record?
Just as you have manually edited the record, you can manually assign it as your half-marathon personal record in Garmin Connect. After that, you can even instruct Garmin Connect to send it to your f?nix?5X and overwrite the entry that is on the watch.
You set a personal record manually by bringing up the activity in Garmin Connect, then click on the cogwheel icon, and select 'Set as PR' from the drop-down menu.
