I am having extremely slow wifi speed issue. I had no problem with speed in last few years. however, this is my 3rd time that I have a problem with speed this year.

On Saturday, wifi speed went slow and it last till today (Monday morning)

Sunday afternoon around 4:30pm, internet speed was 170Kbps and it was 1.0Mpbs in the evening (around 9:30pm)

I followed some suggestions from Telekom website: re-starting router, check router’s FW version, re-connecting WLAN cable. None of them fixed the issue

Then I tried self-diagnosing thing from Telekom website last night. It seemed the issue was fixed but speed again became slow in 5mins

Streaming music or even googling takes a while. It is bad enough to have this issue on the weekend, and I am concerned that it will happen when I am doing home office.

Could you please fix this issue? And if it is possible, could you provide what was the root cause?