LR6 (CC), edit TIF file (imported from PS or NIK). Image "reloads" after almost every Develop module edit. In some cases, all previous Develop module settings are lost, and the image reverts to it's original appearance. Even though the previous Develop module edits are still shown on the History panel - they no longer have any effect. Result - total loss of all user edits.
Workaround: disable "Automatically write changes to XMP" in catalog settings. This is what appears to trigger the constant "reloads".
Note this does not appear to be related to GPU - the problem occurs exactly the same whether GPU is enabled or disabled. Also note, the problem does NOT occur when editing RAW files. So far, it appears to occur only with TIF files.
Lightroom CC, 2015 Release Windows 7, 64-bit, all latest updates AMD Radeon HD 7700, latest AMD drivers