I've had a very specific bug ever since I upgraded to Windows 10 that no one else I've spoken to has seen, and none of the other Windows 10 alt-tab questions or threads seem to cover.
I often find myself working with Word documents or Adobe-reader PDF's open, for reference, often quickly opening one to look up something, then alt-tabbing to another window to type or read something else. however, since the upgrade to 10, these two programs don't like me alt-tabbing and force their way back to the forefront, but only once. it will be simpler to explain with an example.
Lets say I'm writing something into Window A. I need to stop and reference something, so I quickly load a Word document to reference something, call this Window B. I find what I need in a few seconds, then alt-tab back to Window A and continue typing. 2-3 seconds later, Window B is suddenly in front, and my cursor has been set to it, so my typing is suddenly happening in window B. I backspace this out, alt-tab back to window A, and then that's it. It doesn't force it's way back front anymore.
Unless I need to open another word document, Window C, which will again force it's way back to the forefront the first time I alt-tab away from it, but only the first time I do so.
This multiplies endlessly, but only once per file. Word Window D, E, and F will all object to my alt-tabbing away from them and force thesmelves to the front a few seconds after doing so, but only the first time I do so while Word is open.
Adobe Acrobat displays the exact same behavior, forcing itself to the front after alt-tabbing away, but only the first time.
These stack upon themselves. if I read PDF window G, decide to look up something by loading PDF window H, I can only read a few seconds before G suddenly decides I should still be reading it.
but in each case, this only happens once per instance of having Word or Adobe in memory, per document. if I then go from H to I, then H will force it's way over I, but only once. ad infinitum.
however, if I close all Word and/or Adobe Reader windows, and then load the same document, it all starts again, each one forcing it's way to the front exactly once.
To avoid a commonly asked question in response, yes, the same thing happens if I click on another window in the taskbar instead of alt-tabbing.
However, it is not a case of the switch being forced behind all other windows. the window I alt-tab or click on comes to the front, and I can use it for 3-8 seconds before the word or adobe reader window I left forces it's way in front of it.
At first I tried to ignore it, because after forcing it's way up once it'll behave afterwards until the next time Word or Adobe Reader is loaded into memory, but every time I close them to clear up space on taskbar or memory the whole process starts over again and it's driving me nuts I can't find anything about it.