After reaching lvl 20, the icon on W skill has permanently changed to disengage spell. Nothing happened after pressing W, the zombie wall was nowhere to find and impossible to use later in game.
What were the circumstances to this happening? Did you pick specific talents? Did it work properly up until that point? If you picked Vile Infection did you complete the quest? Did you die at one point and did it fix itself when you respawn?
Talents were Widowmakers, Big Voodoo, Deadrush, Ravenous Spirit, GuardianToads, ring of poison, Anihilating Spirit.
it worked fine before it stopped 
I did die after it stopped, to see if skill will reset, it did not help.
I’d suggest watching the replay from your own hero perspective and see if the wall button stays pushed in after the problem occurs. I’m not sure if and how the ability tooltip/button tracking will show in the replay though. If there’s something to work off with from the replay you can email the file with a brief explanation and link to the forum topic.
HeroesBugAttachments@blizzard.com
It does not seem like a consistent issue that anyone on the forum ever ran into and it’s not one that is easy to recreate. I tried for myself using the same talents in Try Mode hoping there’d be an obvious problem that surfaced after the patch but everything worked fine.
the file has just been sent 
Hi, I’ve had the same issue with Nazeeboo Walls getting disabled/button pushed, now i’ve had it in 2 QM matches. The first one occured before level 20 and after level 16. The second one occured also before level 20 I guess, but couldn’t verify as I don’t see the buttons in the replay.
Selected the following talents: Things of the Deep, Blood Ritual, Dead Rush, Ravenous Spirit, Ice Block, Ring of Poison (after the bug occurs) Vile Infection.
Heroes of the storm running on Windows 10
The bug seems to be since 25-09-2019, i’ve never experienced this before playing Nazeebo.
I had the exact same problem today, apparently after the zombie wall got catched on etc´s pogo, one zombie remained alive and it was impossible to cancel it, it persisted the rest of the match.
Yeah, same thing happened to me today, it seems to be the last patch, I have played nazeebo for a while and it never happened before.
Seems to happen when the zombies get stunned by some ability, for me it was etc´s mosh, one zombie remained after dad and never went down or dissapeared.
Hi, I’ve got the same issue. Today a second time. There were neither a stun of zombies nor did they stay permanently. “W” was just disabled for about 8 min. When it occured the first time, it was disabled for the whole game.
the same thing happened to me 2 times already
The sooner you and others can agree and confirm what is causing this, the faster it might get fixed. Just saying that you had this happen to you does not help.
Got the same problem just now in a HL Match. One Zombie seemed to got stuck near a wall. Maybe through ETCs Stun? I dont know, because I just realised it after a few seconds and later found the missing Zombie all alone standing around … 
So lets get this straight, was everyone that experienced this using lvl 7 Dead Rush talent? One that makes the zombies stand up and run after targets for several seconds. It could be that some crowd control effects are bugging them out and the game isn’t properly registering them as despawned to allow next use of the ability.
This seems to have become a common problem recently with many different reports flooding the forum. I’ve played a large number of games on Nazeebo myself without running into this and the only difference between my and other users’ games I could think of is with the talents. I always went Spiders on 1/2/3. Dead Rush is the only talent that somehow mechanically modifies the Zombie Wall. Ring of Poison on lvl 16 not so much, as it only adds a numerical increase in first “half” of the ability duration.