Thunderbolt 4 laptop > Thunderbolt 4 dock > HDMI 2.1 Switch > HDMI 2.1 4K monitor

Although I'm positing this in Windows 11, it also applies to Windows 10. I have spoken to Dell and HP as laptop OEMs, Intel as Thunderbolt/graphics hardware and driver maker, Anker and Caldigit as Dock manufacturers. No one is admitting fault and just blame each other.

So posting here as a last resort. I would be really grateful if anyone who has the means to replicate my setup and testing, can do. Especially Microsoft if they read these posts.

I am an IT Pro so can do any technical testing/changes and/or provide logs.

My typical use case is with the laptop lid closed and Projection setting is 'Second screen only'.

I have 4 source types: Chromecast, PS4/5, Nintendo Switch, and various Thunderbolt 4 laptops (Windows OS, ChromeOS/ChromeOS Flex). For laptop connectivity to the dock, I have a Cable Matters Thunderbolt 4 certified cable loose for me to just plug in on demand.

• All sources are connected to the same HDMI Switch. HDMI switch in turn is directly connected to the monitor. All HDMI cables are version 2.1 certified. My monitor HDMI ports are also version 2.1

• Chromecast, PS4/5, Nintendo Switch all ALWAYS connect properly, e.g. I change to their input on the HDMI switch and they all just come up on the monitor okay first time every time. Zero issues, ever

• ChromeOS/ChromeOS Flex devices connected to the Thunderbolt 4 dock also ALWAYS just work first time every time. Again, zero issues, ever

• However, Windows 10/11 laptops most of the time never come up - I have to repeatedly change input on the HDMI switch back to one of the other sources (even if the device isn't even on) then back to the laptop source input. Or, disconnect and reconnect the Thunderbolt 4 cable.  Eventually it will come on. Sometimes it does happens first time, sometimes it takes 2 or 3 times, of switching between input on HDMI switch, sometimes even more times. So it's completely random as to how it will behave. But what is interesting (I think I test this a few times), is if I bypass the dock and connect a Windows OS laptop directly to the monitor using a USB-C to HDMI adapter, this NEVER happens. It works first time every time

So it appears Windows OS doesn't interact well specifically with Thunderbolt 4 docks. I think this is validated because at my actual work office we have standard USB-C docks, not Thunderbolt 4 ones, and I don't recall ever having this issue.

And the fact that non-Windows OS laptops are okay through the same dock and cable also validates this. Even more so, the ChromeOS Flex device I have is a former Windows 10/11 laptop - when Windows was on it I had this same problem, but I've never had it while ChromeOS Flex is installed.

All drivers and BIOS/firmware are kept up to date. As is Windows itself: according to winver I'm currently on Windows 11 22H2 (OS Build 22621.3447). But no build since I got the current laptop in July 2023 has ever just worked.

As an aside, my monitor supports HDR and all other sources show HDR is being used. However, when I enable HDR in Windows the screen disconnects and never comes back. I have to fiddle about swapping primary screens to eventually be able to see to disable HDR.

Hardware:

Laptop: Dell XPS 13 (this is the current one), HP Spectre x13 (the HP is the one with ChromeOS Flex on)

Dock: Anker PowerExpand 5-in-1 Thunderbolt 4 Dock (Anker even sent me a replacement when I raised this issue with them), Caldigit Thunderbolt 4 Element Hub (this is the current one)

HDMI Switch: 2 different models both supporting HDMI version 2.1 and up to 8K resolution

Monitor: Philips 32M1N5800 4K HDMI 2.1

Console: Sony PS4 / PS5, Nintendo Switch gen1

Streaming: Chromecast with Google TV 4K

Thanks for reading!