Button text disapears after months of working fine


    I have a field service reporting android app that I created in Oracle MAF. it has been in use for almost a year now with no UI issues, Over the last few days, I have been getting reports from our end users that the button text is disappearing. so - anywhere where there is a button with text inside it, the text is not visible. The last android update for the device was weeks ago, and the problem is slowly propagating, like only 4-5 users a day are reporting that they go to use the app and the text is gone. luckily they are used to the app and know what all the buttons do, but I need to find a reason and I'm completely stumped. Anyone else seeing this issue?