@ferrari486 I have the exact same issue with my A7 v5 except I get 700mbps from the modem, 500mbps over wifi, and only 300mpbs plugged into the A7. Seems to just be a crap model.

@ferrari486 

If you are seeing nothing higher then 100 Mbps, that might be coming from the Ethernet cable being used. Try swapping the cables from the router to the modem.

@Tony 

I'm using a new Cat6 cable currently. I've tried multiple Cat5e and cat 6 cables. Link speed is always 1gbps.

@ferrari486 

If the device getting 70 to 100 Mbps directly connected to the router gets normal speeds directly to the modem, sounds like something may be wrong with the router.

I seem to have the same problem with a different TP-Link Router.

Modell AC1200

Got a spped update yesterday from 100Mbps to 500Mbps downloadspeed and upload changed from 6 to 25Mbps.

Connecting my PC directly to the modem using the same cable I use to connect modem and router I get 495Mbps download average. And 25 Mbps upload.

As soon as I hook up my AC1200 inbetween (the cable has also been tested directly and works as expected) I get 125Mbps download tops. And upload ranges from 4 to 12Mbps.

Interessting might also be: using 2.4GHz or 5GHz Wifi provides the same speed results as hardwired to the AC1200.

As if all rates where reduced be the same thing.

Btw. I would not expect 2.4GHz to make the full speed due to its limitations. But it should still max out when communicating unobstructed.

Anybody have an idea, suggetion or even a solution?

@Vaengur 

You didn't mention the Model NUMBER/NAME, "TP-Link Router. Modell AC1200" covers a few models.

Should not matter though, the problem probably is QoS set to a value too low, like 100Mbps from the OLD service. You router might have a SPEED TEST (why the exact model matters, I could have looked at the Emulator and could then tell you specifically where to look) and it needed to be run again.

Alternatively you could do a Factory Reset on the router and MANUALLY re-enter all settings (review them before doing it so you know what you had changed, take screenshots if you wish to refer too as well).

If by chance, as part of the upgrade, the modem was replaced, you need to power down both the modem and router, power up the modem first and then, when completely up, power up the router, then test. If you hadn't done this before, I'd try this first if it isn't a QoS issue.