Playing video on Spectre x360 causes external display to malfunction.

[EWDB1]

I have just bought a new external monitor to use with my laptop.  The new set up works ok, apart from some video.  Youtube will play on laptop and external monitor with no problem.  However, playing Netflix or video from Films and TV app and some other video content cause the external display image to go crazy: The external screen will go momentarily blank then the entire image shifts  up and to the right by some random amount, the part of the image that would be off the screen then wraps round to fill where the gap would be from the image shift.  The image also becomes shaky in some areas.  The Laptop display remains unchanged.  It makes no difference which display I try to play the content on the external display behaves the same way.  I am connecting via the HDMI port on the laptop to HDMI on the monitor using the HDMI cable that came with the monitor.  Has anyone else had this problem or any idea how to resolve it?  Moreover, the new monitor has nor HRD options enable in display settings, while the laptop screen has and has always had the streaming HRD content options enabled; any suggestions?

Steps taken to resolve the issue:
Windows update is up to date.
Latest drivers for graphics and audio downloaded and reinstalled from HP website.
Latest monitor drivers installed from LG website.
I have connected the laptop to a TV via HDMI and no display issues. I have connected to a monitor via HDMI to DVI port cable and no issues.  Neither TV nor monitor were 4K, I have no other 4K displays to try connecting to apart from the one on which the problem occurs.

External Monitor: LG 27UL600-W VESA DisplayHDR™ 400, support for HDCP 2.2, IPS 4K.

Laptop: HP Spectre x360 15-bl001na
Intel Core i7-7500U
Intel HD Graphics 620
NVIDIA N16S-GTR-S (GeForce 940MX) with 2048 MB of dedicated video memory
16 GB RAM
1 TB SSD
Built in display IPS 4K

Ports:
USB 3.1 Type-A port
USB Type-C ports 1x USB 3.1 Gen 2 port with Thunderbolt™ Gen 3 technology and 1x USB 3.1 Gen 1 port (all ports support DisplayPort 1.2 supporting up to 3840×2160 @ 60 Hz).
HDMI v2.0 output support up to 3840×2160 at 60 Hz with HDCP 2.2

I have ordered a new USB-C type thunderbolt to DP cable with support up to 8K with backwards computability, I will try this when it arrives, but I am not hopeful as the HDMI cable should work.

The new cable works.  I also took the laptop to work and it worked with the 4K display there over HDMI, so I think the problem is the monitor.  The packaging on it was very beaten up when it was delivered.  I should have thought of this first.

[Riddle_Decipher]

@EWDB1 Due to the current global COVID-19 situation, we're seeing an influx of customers coming in for support and we appreciate your patience.

That said, Considering the device works fine with YouTube and other applications whereas the issue is limited to Film & TV, Netflix alone, you may want to contact the software manufacturers directly for support as if the issue was related to the device, none of the apps would have worked, I hope you understand.

Possible, compatibility issues with the software and other apps/hardware on the device.

P.S: Welcome to HP Community 😉

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