So, did all the troubleshooting steps, even going as far as doing a factory reset and updating to the latest firmware, but to no avail.
I took my S20 Ultra to the service center, and they advised to have the main board replaced. And I will have to wait for two to three weeks for the replacement board to arrive.
I was really disappointed as I have never experienced any factory defect on every flagship since the Note5, not to mention the fact that this is an ridiculously expensive phone.
I emailed Samsung through their Office of the CEO contact page, and asked to replace my unit with a brand-new one instead of repairing my faulty unit. They agreed, even beyond the 7-day replacement warranty, due partly to the quarantine. My new phone is on my way to me now.
If the Wi-Fi switch will not turn on to allow you to connect to Wi-Fi, you can test the phone in Safe Mode.
If you are unable to connect to Wi-Fi while in Safe Mode, the phone will need to be set up for service. Please send a private message with the full model code and IMEI number of the phone. http://bit.ly/2XERsky
Here is the fix guys.
Go to wifi settings.
Tap on top right corner 3 dots
Uncheck switch to mobile data
I use my phone in my basement office with wifi and my router is upstairs but since I got s20 it frequently drops wifi all together even though its not that far from upstairs router. Due.to the option enabled as soon my phone gets weak signals from router it.drops the connection even though home router these days can adjust client if they go far.and put on better frequency.
No further drops and signals stable
Let me know if this helps