Spotify with Strava is causing volume to automatically maximise/minimise

[liviajones]

Description
Please describe the problem
Example:
After using the Samsung Galaxy S3 with Spotify and Strava running at the same time, the volume automatically re-adjusts itself to either maximum volume or minimum volume when listening to Spotify afterwards.

I have had two Galaxy S3's where this has been a problem, the last one I thought was a hardware issue but now it's happened on my newest phone on the same day I run Spotify and Strava together suggests there is a conflict with both of these apps.

What are the steps you took to get to the error/issue?
1. Installed spotify
2. Downloaded a playlist with about 60 songs on
3. Opened Strava app and turn GPS on
4. Start recording ride/run
5. Open spotify
6. Click play to begin playback
7. Begin running
8. Finish run and turn GPS off
9. Within the same day (1hr after run - 8 hrs after run) the volume (without me touching it) re-adjusts itself to maximum sporadically
10. I re-adjust back to normal volume, sometimes it automatically goes back to maximum
11. This happens infinitely regardless of whether I have headphones plugged in or out
12. I have to take out the battery to make it work okay on my latest phone - on my previous phone, this didn't resolve the problem.

What I expected to happen
The volume to be controlled by own volume up/down commands and to not be automatically adjusting

Did you restart your device when troubleshooting in section B?
Yes

Did you read the connection troubleshooting tips?
Yes

Your device
Samsung Galaxy S3

Device’s Operating System
Android 4.1.2

What type of account do you have?
Free

(FYI for the below points: Android devices tend to refer to the internal memory as "SD Card" and the SD card you inserted yourself as "External SD Card")
Space left on your device
11.35 GB

Space left on your SD card (if applicable)
11.25 gb

Space left on your External SD card (if applicable)
N/A

Is your device rooted?
No

Are you using a custom ROM, if so which one, exactly?
No

Did you set your external SD card as storage location?
Yes for images

Did you manually install an older version before installing the latest version from the Play Store?
No

Do you have the same issue when switching between WiFi/Mobile Data (If applicable)?
Yes, wifi or no wifi it doesn't make a difference

If you said "No", when does the issue not occur?
N/A

My mobile Spotify version
0.7.3.636

My desktop Spotify version (if applicable)
N/A

My mobile provider and country
Vodafone, UK

My username
Livloud

Do you have a Spotify (non-Facebook) login?
Yes

Are you logging in with Facebook or with your Spotify login details?
Spotify login

Do you have any screenshots you can attach to more clearly explain your issue?
It's the Samsung Galaxy S3 volume bar on maximum  - it won't help much

[Peter__]

Does this still happen if you use a task killer to kill the apps once you are done with them (wondering if they are running in the background still)?

[liviajones]

Yep, I cleared all other background tasks.

With my previous phone (where this problem happened alot more - but where I also used Strava and Spotify together alot more) a task killer or factory reset didn't help either