iPad Mini 4 Brutally slow, unusable after 13.3 updates

So toss it and buy an Android? I have 23 years in software development and advanced technical support.

Have owned the mini for about 2 years. Performance never an issue until the 13.3.x updates. I use it daily.

It is so slow as to be insulting. Have never even see a performance drop like this from Windows 3, XP, Vista, Windows 8, or Windows 10. Performance is about 40% drop since the latest iOS updates.

I use it exclusively at home via wifi. I have 15 devices on my network. All working aOk no issues with any devices, just the iPad Mini 4.

Have even reset my router a number of times just in case. Fixed DHCP addresses assigned to each device, no guest access permitted. All other devices are very fast. Desktop PC, laptop PC, Kindle, a few Android phones, music server, etc.

All apps affected. Safari the worst. Takes up to 50 seconds to load a webpage. Before 13.3.x, maybe 2-4 seconds tops.

iPad has 40GB free space of 64GB total.

Have done a full reset of the iPad Mini 4. Then turned these all off:

Siri

Al Notifications

all background app refresh

All motion related features

Deleted all of my largest apps, such as Tidal, Kindle, ZINIO and reinstalled each.

Tested iPad speed before reinstalling those apps. No difference, everything still slow.

Installed Google Chrome to compare to Safari. It is equally slow to load web pages.

I have left it powered on and plugged into AC and on wifi for days at a time in case this was some post indexing issue after the 13.3.x updates.

Have googled similar issues on the web and followed all other suggestions from many articles.

i can see no settings left to adjust to improve this.

If not for my music server (Auralic Aries) that only works on Apple devices, I would toss the iPad and use it for a bookend and get a Android tablet. My wife’s 3 year old Samsung tablet is blazing fast, puts the Mini 4 to shame. She has never had a performance issue on that device, where the Mini 4 has suffered several of these issues after iOS updates.

Any ideas?