I added Strava to my activity trackers yesterday because it has activities since 2018 while my Garmin is active only since 2020. After about one day, still only few Strava activities are sync’d (or displayed as Strava ones; Garmin syncs towards Strava). Adding a single one works immediately and according to https://citystrides.com/status there is no delay.
Do I need to pause Garmin to have only one tracker active?
My profile link :
You don’t need to pause Garmin.
Let’s see how this manual sync I just started helps out…
Unfortunately, no progress and still only 762 activities (3 automatic and 1 manual sync’d from Strava out of 1110 running activities).
I was able to get your count up to 1001, and I might have found an issue in my sync code along the way. I’m unsure what the other 109 activities could be, though.
Is it possible you’re including treadmill, non-run/walk/hike, or otherwise “GPS-less” activities in your count?
1.101 running + 8 hiking + 179 biking + 2 swimming + 5 training is less than 1.311 total list in Strava itself
There could be some tracks with bad GPS quality. Considering issue as solved.
Thanks for support 
After spending more time on clicking through the pages, I found out that activities from mid August 2019 to mid February 2020 were missing (except 14.6 km Run Activity on January 28, 2020 by Steffen19 W. on Strava that I put in the queue) although GPS quality seems good…
PS: Is there a quick way to import the activities 3108123462, 3091455380, 3085822027, 3082669789, 3077441612, 3071441186, 3065990761, 3062047860, 3057199739, 3051422627, 3047357508, 3045936164, 3041574548, 3037175523, 3031296706, 3025689271, 3022366896, 3017032768, 3011256657, 3005271652, 3002040130, 2996193530, 2993883813, 3008102783, 2987591389, 2984504052, 2978363110, 2975448116, 2971991906, 2971887841, 2965407054, 2953278703, 2949433057, 2946819888, 2945154517, 2940886392, 2938189372, 2936918870, 2934272932, 2930556385, 2928546203, 2925987226, 2924528494, 2922130817, 2919795827, 2917155994, 2908981061, 2904557837, 2901802542, 2897886198, 2893255477, 2900406760, 2888774951, 2888638255, 2885360889, 2881631880, 2876900325, 2871913894, 2868962286, 2864132987, 2855514874, 2852577605, 2848091561, 2839862759, 2837421733, 2832542959, 2826721665, 2824285574, 2823252887, 2821637664, 2820868956, 2818182914, 2812761255, 2808934460, 2803804050, 2803586098, 2800561486, 2796470687, 2791594403, 2791377604, 2789970877, 2789078199, 2787590925, 2785540275, 2783037258, 2778521467, 2773387880, 2766922867, 2759221215, 2755133488, 2749639954, 2746356567, 2744257680, 2742034010, 2739500242, 2734725122, 2733746042, 2731105876, 2727607744, 2725673501 from Strava?
I fixed up some queueing issues in the past ~week, so let’s see if another sync fully resolves this issue. There’s no sync backup, so we should know within an hour or two. Let me know either way.
Unfortunately, that fix did not solve the issue.
After 7hours, I lost my nerves and queued the 100 IDs mentioned above with a little bash script.
Because those IDs are extracted by only one page the Strava API with per_page=100, the activities between September 21 and August 8, 2019 are still missing.
Shall I do the same trick or do you need them to be out of sync for debugging, James?
I’d prefer to debug, to fully resolve whatever issue is causing this problem, but I also understand you may not want to wait for me.
I may have some time tomorrow & the next day to review this.
Looks like you fixed the problem. When logging in today (from another device), all activities are shown.