P: Slideshow Export video hangs if the mov video has quick develop settings applied

Lightroom 9.2.1 had this problem, I was hoping 9.3 would fix the bug. It doesn't!

If you create a slideshow which contains mov files, if you do no changes to the mov file, the slideshow Export video works fine. However, if you change the mov file white balance or tone (e.g. in the library quick develop panel) then try and export the slideshow as a movie, the process just hangs forever.

Does anyone else see this problem? can you try and reproduce.

My mov files are created by a Fujifilm X-T3, I'm using MAC OS Catalina 10.15.5

Here's my system information:

Lightroom Classic version: 9.3 [ 202005281810-476e492c ]License: Creative Cloud
Language setting: en-GB
Operating system: Mac OS 10
Version: 10.15.5 [19F96]
Application architecture: x64
Logical processor count: 8
Processor speed: 4.0 GHz
SqLite Version: 3.30.1
Built-in memory: 24,576.0 MB
Real memory available to Lightroom: 24,576.0 MB
Real memory used by Lightroom: 1,759.6 MB (7.1%)
Virtual memory used by Lightroom: 7,041.7 MB
Memory cache size: 39.8MB
Internal Camera Raw version: 12.3 [ 493 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 151MB / 12287MB (1%)
Camera Raw real memory: 204MB / 24576MB (0%)
Displays: 1) 5120x2880

Graphics Processor Info: 
Metal: AMD Radeon R9 M295X