After having reached out to Garmin support 10 times regarding instant pace inaccuracy with my Forerunner 245…I have now given up. But I have found a workaround:
I have now removed instant pace from my main display and just added lap pace. The lap is set to 1km, so now I at least have a semi accurate reading of my pace for that specific km. if I am doing shorter intervals then I just use the lap button accordingly. It’s not ideal but it does the job for now.
I am shocked at the lack of response from garmin. This will be my last garmin watch and I will switch to Coros.