Why does my chart widget display a different numeric percentage scale on different phones?

We use dashboards extensively with remote teams. Most people have no problem accessing and seeing information correctly on the mobile app. I have one person, the President, that see the numeric percentage scale differently on his phone. No problem on his desktop and I'm not aware of anyone else having this issue. I have two pictures attached. One is what he is seeing and one is what I (and everyone else) is seeing. Anyone know what's going on with his phone?

thank you,

Sean