Thanks for posting. I am very sorry to hear that you are having this issue, however I would love to help.
Firstly, I would recommend ensuring that you are running the latest version of the Bose App. If you are running the latest version of the app and the issue still persists please delete and reinstall the app.
I look forward to your reply.
Hector B - Community Support
Whilst we appreciate your hesitation and frustration, in relation to your previous Play All issues, in version 19.0.5 we applied security updates to our SoundTouch products to address the WPA2/KRACK security concerns. We conduct compatibility and regression testing to ensure any new updates are stable and meet the needs of our customers, although occasionally issues may appear as a result of changes made outside the control of Bose. During the investigation of the Play All concerns, we identified an incompatibility between certain customer-deployed Wi-Fi networking gear and the 19.0.5 firmware update containing the fix for WPA2/KRACK. This update was released in October 2018 to address and resolve the issue that you would have been experiencing. All firmware updates that we release contain important safety and security improvements, as well as general bug fixes and stability improvements. The current firmware version for SoundTouch speakers as of today (19 May 2019) is 20.0.10 and I encourage you to update your SoundTouch speakers if they have not already been updated so far. Additionally, the current SoundTouch application version for Apple iOS devices is v21.0.7, which was released 9 May 2019.
In relation to your current issues, we'd love to suggest some additional troubleshooting suggestions to try and resolve any issues that you're currently experiencing. Firstly, as background information, how long has this issue with the volume been ongoing for? Do you have multiple devices with the SoundTouch application installed on that you've used to test as a point of reference for comparison in results?
A great step to try and alleviate any potential slight errors is performing a reset on the SoundTouch devices, and the internet router. This can be done by disconnecting all speakers from power for at least 60 seconds. With the power still disconnected, disconnect your internet router from power and allow to rest for at least 60 seconds. After 60 seconds, reconnect your internet router back to power and allow several minutes to regain access to the internet. When your internet access has been re-established, reconnect the SoundTouch speakers to power and allow to fully boot. Then, re-test your speakers and volume controls.
The commands to adjust the volume are instructions being sent directly from your phone, via the internet, to the connected SoundTouch speakers and as such I find a great starting point to perform a brief reset on the hardware to test for results.
I look forward to hearing back from you. Should the issue persist, we can attempt some additional troubleshooting.