@ArieKel 

Hello Arie, thank you for reaching out to us and welcome to the TP-Link community.

Did you upload the old config file into the new firmware or have you tried resetting the router and reconfiguring it from scratch when testing the wireless speed? Please try resetting and reconfiguring if you haven't tried that, just to exclude any special settings on the old firmware that may not work properly on the new version.

When doing the reconfiguration, please don't modify any advanced settings such as QoS, just set up the internet and wireless networks, then test the speed.

ArieKel wrote

@Kevin_Z 

 

Thanks for the feedback. It made me think about some standard settings I changed some time ago.

 

With the old firmware I had to set the WAN port speed to 100Mb/s since the Auto Negotiate (and 1000Mb/s) caused my internet connection to drop regularly. With the 100Mb/s setting I only experienced 1 or 2 short drops per day.

However, using the new firmware the 100Mb/s setting on the WAN port causes the internet speed to drop. I have set it back to Auto Negotiate and internet speeds are back to normal (up to 75Mb/s over wifi; 75Mb/s is the max. download speed of my internet connection).

Thanks for your help! 

 Hello @ArieKel, thank you for getting back with the good news. That will be a new clue for the speed issue when coming across to the troubleshooting, we will pay attention to that also. 

I'm going to mark your answer as the "Recommended Solution" so others can be confident in benefiting from it. Good day.