504 error when installing Facebook on a Galaxy Tab 4

[AC Question]

Problem started some weeks ago possibly after an upgrade. Facebook shows as not installed so hit install in the PlayStore, it installs and then optimizes and this happens after every restart. Temporary solution, don't turn off the device. Eventually the tablet restarts, maybe an upgrade, who knows and now Facebook will not install, gives 504 error. Two online Google support guys later and every forum suggestion I can find. Reset the device, cleared the cache for Play Store, reset the date and time falsely, restarted our network devices, force restarted the tablet with the power button, installed other apps(Pinterest, Weatherbug) no problem.
EXHAUSTED, seems the only choice is a new device
Samsung Galaxy Tab 4
SM-T330NU
Android 5.1.1