@Kevin_Z 

I know this is an older thread, but I just couldn't resist....

'smart DHCP'????  You guys have hundreds of posts clearly stating that DHCP IS DISABLED when running in AP mode.  If this IS a valid feature, why isn't it described ANYWHERE in the documentation?  Aside from that, we, as consumers, should be given the ability to disable this so-called 'smart' feature.  

I might have an odd configuration here, but I can just about guarantee that I am not the only one with the same or similar setup:  I have a local file server that manages all DHCP and DNS traffic in my network.  This server is set to reboot bi-weekly for stability purposes.  The problem is that when the server is rebooting the Deco unit (mine is an M4) assigns random DHCP information to the server before the server's DHCP becomes active.  In turn, every device on my network is handed out this random information, which most importantly contains a truly random default gateway address, and my entire network collapses.  I have wasted many hours of time and frustration trying to correct this issue that did not exist until the Deco units were installed.

I did many hours of research before to make sure that this unit did indeed disable its built-in DHCP server before I made the purchase.  Now, I am severely regretting it.  This is a function that needs to be fully documented and WE, as consumers, need the ability to be able to turn this function off permanently.

@Kevin_Z This functionality is anything but "smart".
Once your devices get a lease from the DECO acting as a (wrong) DHCP, your network is almost destroyed, no one can access the Internet because the gateway address will be wrong, and re-connecting the good DHCP will not solve the problem: you must cycle (disconnect/reconnect, reset, or unplug/replug) all the devices that stay stuck on the wrong addresses. Why should you need to get an IP in a network without a valid DHCP server? to repair the DHCP, I guess. So, how can you repair your DHCP server if, for example, your "smart" DHCP is giving you an IP in another segment??? (yes, it happens, it's very probable after a power blackout).

You are receiving complaints about this for more than a year, I'll stop suffering the issue in the simplest way: disconnecting your products from my network.

thank you for your time.

I'm having the same problem.

Really disapointed with TP Link right now and considering returning my M4R units as without much needed updates and diligent fixes, they are useless to me.

In order to by-pass this issue (which is also causing older devices to randomly loose internet connection - without loosing any wifi bars), I assign static IPs for each device in my router and every smartphone (deco works in access point mode). In this way, each device has the IP address preconfigured and when for any reason any deco satellite restarts, internet is not broken when it cames back.

I am having this same issue. For no reason I can see, the Deco m5 enabled its own DHCP server which changed all my addresses for my home automation systems which rendeder my entire home inoperable.  I spent 5 hours until 2am last night trying to figure this out, and finally narrowed it down to the M3 devices being rouge DHCP servers.  I can see on several devices that they have the M5 as the host router.  But I am in AP move and never used router mode ever.  

THERE NEEDS TO BE A WAY TO ENSURE HDCP IS NEVER, NEVER, NEVER, NEVER ENABLED!!!!!!!!!!!!!!!!!!!!!!!!!!

@Kevin_Z 

This not an OK response to the inquiry, however, on the plus side, I can now confidently trace all of my network problems back to this "feature".

I had been looking to upgrade to a newer set of TP Link devices, but there's no chance of that happening now.

I'm ordering a new wifi system today and posting this one on craigslist, or better, throwing it in the trash so no one else has to put up with the BS.

Farewell!

Edit: Just placed a preorder for the new eero Pro 6 tri-band mesh Wi-Fi 6 router