MacBook Air M4 Won't Detect Multiple Displays From Thunderbolt Dock

This is a well known crossplatform bug.

USB/Thunderbolt & Energy Saver/Sleep/powe… - Apple Community

There are many reports of Thunderbolt 4 not being as responsive and capable as the firmwares either of the computer or the docking stations, or monitor need upgrades.

SeanTheBon wrote:

Thank you. I appreciate your diligence. I'm still uncertain why it works on the M1 (running Sonoma) and worked on the Intel before it was updated, but so be it.

Two possibilities:

• You installed the DisplayLink driver software on the M1 MacBook Air – but have forgotten that you did that. So the DisplayLink-based outputs work on the M1 (in a second-class way), but don't currently work on the M4 as you have not installed the driver on it.
• The dock drives one of its outputs in a hardware-supported way. When you were using it with the M1, you had your monitor plugged into that output. When you moved the dock to the M4, you plugged your monitor into a different output – one that either requires installation of a DisplayLink driver (see above), or one that uses the equivalent of DisplayPort MST daisy-chaining (which the Mac does not support).

Is there a Thunderbolt docking station you would recommend that is known to work with Sequoia?

I don't know about Sequoia per se, but I'd suggest looking at Thunderbolt offerings from Other World Computing, SonnetTech, and CalDigit. Those vendors have been in the business of selling Thunderbolt gear to Mac users for a long time, and I'm assuming that all three have competent pre-sales and post-sales support.

P.S. – The manufacturer mis-spelled the word "Display" at least four times. (See column headings below.). And I'm still not finding any place where they refer to the dock as a Thunderbolt dock, rather than as a Thunderbolt compatible one."

Thunderbolt docks almost never require downloading and installing drivers for DisplayLink or some other similar workaround. (I think I've only heard of one genuine Thunderbolt dock that was an exception to this rule.)

The manufacturer refers to this as a "DisplayLink docking station" and a "Triple Monitors Docking Station", and there are hints that one of the video outputs might rely on DisplayPort Alt Mode (rather than on DisplayLink). It might also rely on the equivalent of DisplayPort MST daisy-chaining since the description says that you can use four monitors with Windows but "only" three with macOS.

Nowhere do I see the words "Thunderbolt dock".

I'm not sure that is a Thunderbolt docking station.

TobenOne – UDS033 TobenONE DisplayLink Docking Station Triple Monitor with 120W Power Adapter

"Purchase Notes

This docking station 3 monitors requires downloading and installing a DisplayLink driver before use. 

NOTE: for macOS, Please follow these steps: Privacy & Security > Screen Recording > Allow "DisplayLink manager" to join in".

In other words, it is driving at least some of its video outputs using a second-class workaround.

"Note: DisplayLink has a few scenarios where it’s not the right fit such as gaming and HDCP (copy-protected) content playback from Blu-ray/Netflix/Prime/ iTunes/Hulu/etc. Not recommended for gaming or software requiring a dedicated graphics card. Not for gamers"

The description says that

"The DisplayLink docking station is compatible with Thunderbolt 5, Thunderbolt 4, Thunderbolt 3 and full-featured USB-C laptops, with macOS 11+ systems, Windows 10 or later, Chrome OS 100 or later, Ubuntu, and Android. DON'T support Linux/Unix. Note: Requires installation of DisplayLink Drivers before using!"

but that doesn't necessarily mean a thing. Lots of vendors of "plain" USB-C docks and adapters advertise their devices as being compatible with Thunderbolt. The reasoning goes something like this: Every Thunderbolt 3, 4, or 5 port, by definition, has a USB-C connector. Such USB-C ports tend to also implement other protocols such as USB and DisplayPort Alt Mode that are the ones that the "Thunderbolt-compatible" device really uses. Therefore, claiming Thunderbolt "compatibility" is a way to reassure Mac users that a device will work with the "Thunderbolt" ports on their Macs (which are actually multi-purpose USB-C (USB, DisplayPort Alt Mode, Thunderbolt) ports).

The thing may cost as much ($219.99) as some genuine Thunderbolt docks do, but from what I am seeing, it is not a Thunderbolt dock.

I would not blame the M4 MacBook Air for the problems you are seeing when trying to use it.