@AlanQ 

Yes! I have the same problem. After upgrading to 1.4.2, the slave deco would drops from 100Mbps to 20Mbps without reason after some time. I have the slave deco with an ethernet backhaul. Tested no problem with other AP. 

I need older firmware.

@Kevin_Z can you please enlight this?

Any reply or progress on this? I updated my decos a few days ago and now having serious problems. Slow internet, main deco disconnect wan, multiple errors in log and no internet for more than 5 min.

Update: so after trying everything in router mode, I switched it to Access Mode, lasted 20 mins then went back to not having internet. Seems firmware is broken

@CoPf 

My temporary solution is to change from access point mode to router mode. After the deco reboots, I delete network from the app. Then set up everything from scratch. 

It's been two days or so. I haven't face any speed reduction so far... Will report back in maybe a few days more.

@jacktiew I had tried that, still failed. I finally got in touch with their support and did a remote session with their senior tech, which upgraded the GDPR as well downloaded another 1.4.2 firmware.  so far been over 30 mins and problem seems better. The only thing i see right now is that the GUI from the laptop side lags tremendously, and the system info, logs and such fail to load. 

besides that seems to work fine. I'll update after a week 

@CoPf 

Any idea on how do I talk to their tech support? I'm curious.

@CoPf 

Does the problem still happening to you after the remote session from the support?

@jacktiew so after testing it 24 hrs the main deco failed again and went into offline mode. I did another hard reset on all of them. Then reset everything again. So far been a few days and it's good. Speeds are ok. There is intermittent disconnects when I'm upstairs bedrooms of my house but it's not common. I would say problem is 90% fix. If you need to reach them. Go to their online chat first. Tell them about the issue you have on 1.4.2 then after ask for remote session support. They will create a ticket and schedule it with you. 

Note there is new firmware available don't know if this will fix your issue. 

@CoPf 

I already update the firmware and give it a hard reset last night. Let's see how it goes. Thanks for the head up. :)

@jacktiew let me know, I don't want to update mine yet. In case goes dead again.