Same here, just started acting up again on me. I initially had this problem at launch of the new xpac as well. Reached out to technical support three times and just got a canned response about connection issues & telling me to check the forums. Posted in forums about it with many other people experiencing the same issue. After several weeks and other updates, the problem finally resolved itself. This has been an issue since launch of TWW. I wish technical support would look into the issue.
I’m having this problem also except WoW.exe isn’t even coming up in task manager. I click play and it says “Launching…” for several seconds before reverting back to “Play” over and over again. I’ve checked my drivers, uninstalled/reinstalled battle.net and WoW, scan and repair either doesn’t work at all or only works to launch the game once then I have to do it again when I open it back up. I’ve had this problem a few times now, I don’t have the xpac yet and this happened during DF.
That is exactly how mine acts. I did a full reinstall, which fixed it (5th time now?) then they launched another update and it’s broken again. I’m out of ideas. Support has no idea what to do and the team doesn’t feel it’s important enough for them to investigate it.