Problem with physical button volume

Hello everyone,
I have been using volumio with Spotify connect for a long time, but now even more because I have switched to qobuz! Besides, I take this opportunity to say what happiness and sound quality with volumio and my audiophonics! But if I come here it’s because I have a little problem. In fact, I pilot volumio from my Android devices, either with the application found on Google play or with the browser, but for both, I cannot change the sound volume with the physical buttons on my phone. I can always turn down without any worries but if I want to go up it always hangs around 24 and I cannot exceed this figure but also using the volume screen icon which allows to increase. Do you have any idea or solution to this problem?
Thanks in advance for your help and reply