Wow, no one has even replied to this over the past 3 days?  C'mon folks.  We need input if there are improvements or new/old issues.

Please take a few mins to give feedback If you have upgraded to this new firmware.

@Mystiky 

This thread seems to be where most are giving feedback after upgrading: https://community.tp-link.com/us/home/forum/topic/177078

@Mystiky My WAN connection was completely destroyed. 

If I hooked up directly to the modem itself I get full speed that I pay for, however, connecting through the router (wired and wireless), speed tests consistently timeout and if they do succeed in starting I get a max of 350Kbps (yes... kilobits) with pings over 1000 (normally around 20-30).

I verified that both wired and wireless transmission between machines inside the network are stable and full speed. 

I've attempted to release/renew WAN and that changed nothing. 

Finally, I factory reset the entire router, reset everything up, and am back to full functionality. 

Not the best experience for a firmware upgrade, but at least it isn't bricked.

@ShankRabbit Thanks for the comments!   So from what I understand, after you FACTORY RESET the router, everything is now working?

If this is the case, then it makes perfect case as I think that evryone should do that after any firmware update.   It probablly takes 5 minutes to copy and paste everything back into the unit and you know that all is clean.

@Mystiky From a "I work in the tech industry" point of view, fine, doing a factory reset isn't a big deal as I know my network well enough to do that. 

From a "consumer product" point of view, it was a garbage experience having to troubleshoot the issue. Firmware upgrades should just work, not require factory resets.

@Mystiky before this firmware update, I was occasionally getting the '2.4 no longer exists' issue, but only after having the router on 24/7 for 2 to 3 weeks.

Now, with the new firmware, I can't confirm if that's fixed or not due to a brand new issue: if the router has been on for several hours, when attempting to Chromcast from any devicez it won't see any of the devices on my network (I have 2 Google speaker, a Google hub, a Shield, and a smart TV).  The moment I restart my router, all devices will show up under Chromcast again. So now I've been restarting my router 2-3 times a day to fix this... 

I never had this issue before the firmware update, I'd gladly take 2.4 breaking once every 2-3 weeks over this...

I've factory reset my router twice, but the problem still persists.

Also, on top of Chromcast breaking, the wireless sync option for Comicrack to sync my comics between my Windows PC and my Android tablet also stops working.

Any ideas on how to fix this?  Hoping I just have a bad setting somewhere or something....

@Mystiky 

Since updating last week many of my 2.4 devices loose connection several times per day. Rebooting the router solves the issue for a few hours. Before the update everything was perfect since I bought it several months ago. I wish I could roll back the firmware. 

@Mystiky 

Here the same problem whit the last firmware for the X6000 it have te same problems  the AX11000 same router only whit 5 ghz extra

@JP8105 

Performing a factory restore and turning on Smart Connect seems to have solved my issue for now.

@Mystiky  Hi, hope evryone is safe and sound at home. We are stil looking forward to onemesh firmware upgrade. Any timeline on this? I personally purchased this router because Onemesh was. "comming soon". 8 months later no onemesh feature has been released. I have also purchased two re505x range extenders which are not working as intended because ax11000 is not onemesh enabled. please help!