System notifications don't display on DisplayLink monitor
 

I've been using a MacBook Pro M1 running macOS Tahoe 26.5.1, connected to an HP USB C/A Universal Dock G2, with an external Samsung SyncMaster 2243BWX monitor attached to the dock's HDMI port via a DVI to HDMI cable. I have had no problems getting system notifications to pop up on either the built-in display or the SyncMaster, depending on which one was designated as the "Main display" in macOS Display settings.

However, I've just replaced the M1 MacBook with an M4 MacBook, and otherwise retained the same hardware setup. Now, however, notifications won't display on the SyncMaster if it is set to the "Main display". They will display on the laptop's internal display if I have set it as the "Main display", but as soon as I switch the "Main display" to the external monitor, notifications stop appearing. I *can* see the queue of notifications if I click on the notification center on the top right of the screen, and if I switch to use the built in display as the "Main display," all the queued notifications suddenly "pop up" there, but they don't "pop up" immediately like they should on the external monitor when it's set to "Main display". It's almost like when the "Main display" is set to the DisplayLink enabled device, all the notifications get queued up as though the display didn't exist, and then are delivered as soon as a non-DisplayLink display is designated the "Main display".

Since the M4 MacBook Pro has an HDMI port, where the M1 didn't, I *can* plug the monitor directly in there rather than the dock. I have done this, and verified that notifications display just fine when it's connected directly. It's just when I connect through the dock with DisplayLink that they don't display. I can use this as a workaround for now, but I'd prefer to use the dock since I'd prefer to have just a single cable to plug in when connecting/disconnecting the laptop.

I am currently running DisplayLink Manager 16.1 (Build 25) on the Mac, and firmware 1.1.25.0 Rev.A on the dock itself.

Any idea if there is a solution to this?