Dell Inspiron 17 5000 series. Bought 9/2018. Now on Windows 1909 but problems started after the update to Windows 1809 on 7/1/2020
After installing that build Dell support advised to urgently update Qualcom QCA9377 802.11ac driver to 220.127.116.116.
I am fairly sure that this is when the Wifi problems started (not sure because I am mostly on an online connection) End of November Wifi speed was around 180.Mbps. Now it is down to 17Mbps
I have asked them to return to the older build of the Qualcom driver to see if that solves the issue but they want me to call their paying helpesk. I have had experience with those guys. Buying a Wifi dongle will cost much less.
I hope I can get some help here.