My ice maker in my house quit dumping ice and the cause was minerals in the water had pitted the tray. I changed the tray about every two years and solved the problem. I know when traveling and using water from all over the country you are going to get hard water and the filter will only filter so much. Check your tray by feeling it and if it isn't smooth it gets into the little pits and won't release. Try changing the tray and see if that works.