R6900v2 Slow ethernet speeds after firmware update

[iDini]

Today it triggered me too much with past few days of getting slower speeds than I usually do when downloading games. I tried everything on my PC because I thought it was my PC then it hit me that everything was fine till a firmware update. I rolled back my firmware to R6900v2-V1.2.0.76 and FUNNY ENOUGH it fixed (temporarily). About 2-3 hours later it decided to start acting up again. Please give real support, asking about cables, PC will help me none. I have cat 8 ethernet cables from the modem to router and router to PC. This was never an issue before till firmware update. I need firmware and netgear support, that is all. The only way this can be fixed is if someone tells me a certain firmware to roll back to where this never existed or for someone to actually update the crappy firmware we are stuck with so this doesn't happen anymore.

[FURRYe38]

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?

Are you speed testing wired or wirelessly? 

What channels are you using? Auto? Try Auto and 48 on 5Ghz. Or try setting manual channel 1, 6 or 11 on 2.4Ghz and 40 to 48 channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

Has a factory reset and setup from scratch been performed since last FW update?

Be sure your using good quality LAN cable between the modem and router. 

[iDini]

I have the latest firmware now (still obviously no difference which is why I went back previously).

Not sure of the ISP modem but this should not matter since it works fine and has always worked fine till NETGEAR firmware update. 

I am testing wired and wireless, on wireless devices it performs as it should.

I am using auto on both 2Ghz and 5Ghz but once again, should not matter as ethernet/wired is the issue.

Yes wifi neighbors the same amount I have always had, before the NETGEAR FIRMWARE UPDATE this has worked fine for years.

I haven't factory reset because the pure frustration of reconnecting 20+ devices and it not having any impact on the wired ones.

I am using the same LAN cable I have always been using which was fine before THE FIRMWARE UPDATE. This can ONLY be fixed by a rolling back to a specific firmware or by the devs actually patching this.

[FURRYe38]

Yes modem information is helpful.

Yes a factory reset needs to be tried to see if it resolves anything. 

[iDini]

Well I'd go out of my way to find the modem information but it'd be pointless since it's the latest one from my ISP and is fine when connected directly to my PC (meaning this is not a modem issue). As well as it being fine wireless and only wired to the NETGEAR ROUTER is being affected. 

I did try a factory reset, it did nothing. I wonder why, maybe because it's still on the same firmware that is still broken.

[FURRYe38]

Still don't know about the modem. Would be helpful. 

Try downgrading the FW then...