After latest update of Xcode, Web Inspector is not working... any ideas how to fix?

I've posted this as a bug on Apple's Bug Report site. I thought I'd post here too and see what I can find out as to how I might fix this...

Area:

Debugging WKWebView with Xcode using Web Inspector in Safari. I'm running on MacOS Mojave Version: 10.14.3 (18D42).

Summary:

After letting upgrade of Xcode run (Version 10.2 (10E125)), when I pick the proper Device option from Safari's [Develop] menu (Version 12.0.3 (14606.4.5) of Safari), the Web Inspector comes up while running the app like before, but it displays as basically blank and useless.

Steps to Reproduce:

1- start iOS app in the Simulator that has a WKWebView that is successfully displaying a web page that has runnable JavaScript in it. (Figure 1) Here I've picked the iPhone 6 Simulator in Xcode

. (Figure 2) App running in simulator... WKWebView takes whole screen

. (Figure 3) screen after clicking [Run Db Startup Code] button (notice new info under "Test Info:")

. (Figure 4) JS code that runs when this button is clicked.

. 2-Go to Safari window and pick [Develop] menu.

3- Pick Simulator option for the device like: Simulator -- iPhone 6 -- iOS 12.2 (16E226)

4- Pick the "index.html" option (Figure 5) Picking option in Safari after app in iPhone Simulator has been started

.

5- Web Inspector comes up, but none of the page's resources are listed (including index.html) (Figure 6) Web Inspector brought up ... this is the Debugger tab. Nothing appears.

.

(Figure 7) Web Inspector, Resources tab... also blank. Clicking the Refresh button above the Network tab does nothing.

.

6 - Clicking the Web Inspector's refresh button does nothing

Expected Results:

Resources to load, to be able to set break-points on JavaScript lines of code. to have JS code stopped on any debugger; statement to be able to step through JS code and examine current JS variable values.

Actual Results:

As said before, the web inspector window comes up basically empty (like there is no page loaded into the WKWebView at all (even though there is and I can visually see that JS code runs when I click buttons on test interface).

Note: If I try running on actual tethered device, NO option shows up in Safari's [Developer] menu!