there is a seemingly cool app out there called "duet" for iPhones and iPads (not sure if there is and android version) anyway is enables you to use your phone or iPad as an additional monitor and for the most part it worked impressively well until I had a crap load of viewport problems with 3dsmax and it boiled down to the PC version of Duet that you need to install to get the iStuff to work as a monitor.
Anyway if anyone else is having viewport issues and are using duet then try uninstalling that and it may fix your issues.
-dave
Anyway if anyone else is having viewport issues and are using duet then try uninstalling that and it may fix your issues.
-dave