AC3100 Speed Bug / Time Scheduling and Latest Firmwares

  • ATTENTION! As of November 1, 2020, you are not able to reply to threads 6 months after the thread is opened if there are more than 500 posts in the thread.
    Threads will not be locked, so posts may still be edited by their authors.
    Just start a new thread on the topic to post if you get an error message when trying to reply to a thread.


New Around Here
I have been using Merliln for a few years now and started with the AC-87U that is no longer supported but switched over to the AC3100 about a year ago....

So issue is:

  1. Upgraded to firmware RT-AC3100_386.2 final
  2. Was noticing a significant speed decrease on FIOS gigabit from 999-1100Mbps to around 250-300Mbps after upgrade
  3. Downgraded to each version in succession until I got to RT-AC3100_386.1_beta2 where speed returned to 999-1100
  4. However then if I enable time scheduling in parental controls (with NAT acceleration either on or off) the speed drops down to 250-300 similar to above.
  5. Once I turn off the time schedule, speed returns to the 999-1100Mbps again. And I can replicate this as will
  • The newer firmwares above 386.1_beta2; even up to the brand new 386.2_beta1 released today all get the following results that are also fully replicatable:
    • Time scheduling on: ~250 again
    • Time scheduling off: ~300-350M (The Fios speed test even stated to “check the speed of your device” in orange as it knows there is an issue)
  • So in order to get Gigabit speeds, I need to stay at 386.1_beta2 and leave time scheduling off. Very strange issue.
UPDATE: Can replicate with another AC3100 as well that I borrowed. So definitely a Merlin Bug somewhere.

I eliminated switch and cabled Direct to AC3100 from multiple desktops/servers and laptops to check as well. But with the changing firmware per above, as you can see it fluctuates on every device anyway so not cable or switch to begin with but wanted to be sure.

Any help would be greatly appreciated. I may downgrade further than 386.1_beta2 tomorrow to see where the problem started but with the security patches missing, that is not ideal

Last edited:


Part of the Furniture


New Around Here
@mvincent welcome to the forums.

1. There is no 386.2 final today.

After flashing to the latest firmware, reset to factory defaults is required after hitting problems like you are facing. Was this performed for each firmware version you tested/used?

Best Practice Update/Setup Router/AiMesh Node(s) 2021

Thank you. Meant to say 386.1 final in the inital line above...was dealing with so many versions....

I did not factory reset on my existing router between firmwares but will try that. The second unit was factory reset and had the issue.

I read your instructions...Resetting will be a cumbersome task if I always need to do this after every firmware update as I am a power user. I never had to in the past but was mostly in the same version until recently. I have over 20+ Port and Range forwards, not to mention other customized settings for scheduling and parental controls, VPN etc. So if I read your reset procedures correctly, this all has to be MANUALLY entered every time you upgrade the firmware to a new point release and even sometimes even with regular releases???

Can I just cut and paste over whole tables easily even with Firefox export. You cannot just reload the GUI config and *not* the JFFS? I am not sure of the correlation between the two.



Part of the Furniture
The suggestions are only when flashing and you have problems. Only do what you need to, to get a stable router/network. :)

Similar threads

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!