We have the same issue with 3 networks/locations and with ~200 devices. The app can no longer manage these networks because of the mid-string space in the password. Since the Deco app is no longer complying to wifi standards, I hope you will treat it as a bug.

Having to reconfigure means we can't trust TP-link's adherence to wifi standards in the future, and might as well take the cost of changing to another brand and save the reconfiguration time. 

As mentioned earlier Android users can work around this until it's fixed.   Search for an older APK file on a site like APK mirror.  I used a "Deco" application APK from June 2023 and I could use spaces. 

  @pacm 

I just bought the X5400 system today, and I have the same issue with spaces in my Wi-Fi pw.  This is a big issue.  I have too many devices to reset.  Unfortunately, I think I'll be returning this to BestBuy tomorrow. So much time wasted on this. It's a shame because it seems like a solid system otherwise. 
 

  @KamranV lucky you.

I cannot return my five devices due I bought them three years ago but I will not buy any TP-LINK device anymore. Lesson learned for me. 

Honestly I don't know what they are waiting to fix the issue and back to wifi standards compliance. 

  @pacm this just shows that TP-Link should have stuck with making sub-par gadgets. They can't act like a REAL network company. I've already pre-ordered new Wi-Fi 7 gear, and it certainly is not tp-link junk.

  @jgarc This situation is annoying. Also from security point of view is a big issue. Removing one character, they are reducing the number of potential password around 40%.

  @David-TP 

As other posters have mentioned, this is a horrible fix. It goes against good pass phrase practice and it seems I now have to reconnect all the devices in my house! 
Will think twice about buying Deco items in future if this kind of "fix" can be approved without considering implementations

Hi @David-TP, 

Thanks for the head up. It's good to know the Deco App returns to Wi-Fi standard compliance. 

Sorry if at the beginning I was a bit hard with you. It was a really frustrating situation due the amount of devices that I have to reconfigure. 

Thanks to abandon the dark side and welcome back to the light. 

Kind Regards, 

Pedro.