Thanks for reaching out!

What most likely is happening in the situation you described is, since you are recording indoors there is no GPS available which means no distance or elevation is being recorded during your indoor gym climbing sessions. The best alternative if you wish to get your elevation recorded correctly when climbing indoors, would be to create a manual activity and enter your perceived elevation gain. 

If you have further questions, please feel free to submit a support ticket and we’ll be happy to investigate further.

Bizarre request though. I'm a climber, and the ascent is not a measure of achievement. It's the training effect, and those are all different depending on activity type and energy system you are targeting in your training,

Bouldering has a different goal to campus board work which has a different goal to mileage (lead or toprope on longer routes) How much upwards you did is entirely irrelevant.