So I have been seeing this issue which started about 2 months back. Basically, when I upload a third party app generated GPX ride file to Strava (manually), strava forgets about my manually selected bike. I could see the bike show up in my ride acitivity page but give it 1 minute and a web page fresh would have my ride set to no bike selected. I have been editing my rides recently to make sure the selected bike sticks. It is pretty annoying. No discussions I saw online talk about this. Strava support told me they have no solution to that and I should ask in the community. Any help would be appreciated.