I've had very similar issues... I currently have 3 x AP910c's (sharing both 2.4ghz & 5ghz on multiple SSIDs) and a 2862ac (wi-fi disabled)... I had to employ the 'third' AP910c just because of very similar issues to what you describe here.

I use a dedicated 2.4ghz SSID for home automation products and a mixed 2.4ghz & 5ghz SSID for general wi-fi usage.

I wish they could ratify the wi-fi settings pages so we can be certain that different wi-fi capable models are all setup with precisely the same settings. Your mixed model environment must be a nightmare!

Since disabling 2862AC wifi and relying on AP's the system has been performing satisfactory.

On 2862 Central Management > WLAN profile you can set the AP's up then upload the config to the 3 AP

I use it for backing up the configs Central Management >> AP Maintenance >> Select config backup then add the AP you wish to backup click Ok, then move that AP back to LH select box move the next AP over. You can only backup one AP at a time

But disabling the wi-fi on an otherwise expensive router is not ideal... it should work and interoperate with its sister products.

I agree, the 2862 was totally unworkable on WIFI, raised with tech support. They initially used anydesk to have a look, emailed them saying problem continues. Still waiting for a reply.

I have suffered with poor Wifi requiring router daily restarts to resolve, and Adsl dropping multiple times per day. Since installing 3.9.2 the router is now crashing multiple times per day.

I spent many hours with support back and too, as a business class router this class if service is shocking.

I have now removed DrayTek from my setup and replaced with Ubiquiti Edge router, Ubiquiti AC Pro and BT OpenReach Modem. All is now rock solid uptime for 6 days.

DrayTek will not RMA unless I waste more of my valuable time debugging there junk un-tested firmware updates.

Such a waste of £450, I'm too honest to list this item on eBay, but I just might have to but explain why i'm selling.
:oops:

Same experience on vigor 2862Lacm
Wifi 2.4 works but 5Ghz is very bad... i played on all possible solutions but finished by disabling 5G :oops:
Support dont respond and always on vacation !!
Very expensive and useless :oops: :oops: