It has been almost 20 years I have been using gps watches. It is a great disappointment with TH modular 45 paired with Iphone over Wear OS that, it cannot record a simple track correctly under any athird party application.
Watch does not communicate altimeter info with the iphone and does not provide an option to use always watch’s internal gps unit! It shouldnt be that much complicated if TH engineers used to listen to user experiences.
Recently track recording applications started acting wierdly like google fit, which is reducing miles you walked, and instruments app which stopping recording. All these are due to connection issues with ios phones and i believe could be sorted by easily to enable gps readings directly form the watch itself OR TH could develop its own app for sports like running, walking and hiking.

 

I don't know what you are using but i use Strava and have zero issues. Watch works fine stand alone and syncs when connected to my iPhone or together.