My iPhone 15 slow on Wi-Fi during updates

My iPhone has become very slow on WiFi -especially noticeable when updating apps or updating IOS. I tried all the steps I could find on this forum including resetting the network settings - which of course deleted all my saved WiFi passwords. Nothing seemed to work.

Then by chance, I found the answer!

I use Edge as my default browser. I had carried out multiple speed tests and could not get faster than just a few Mb/s. I then tried the same test via Chrome and the download speed was back up to 69 Mb/s. I went back to Edge and the fault has gone!!!! God knows why but it worked for me and I hope it can work for others.

[Re-Titled by Moderator]