@joseph_1979 @KimchiGUN
Thank you both for the responses.
It seems that most routers will display the frequency of the connection with the camera (2.4 GHz or 5 GHz), but few also display the WiFi 802.11 protocol (WiFi 4, 5, 6 or n, ac, ax respectively).
The 2 routers on my network are the Comcast Xfinity Gateway XB7 and the TP-Link Deco 6e. Neither show the protocol used in the connection.
The Trackmix camera is sitting near the Deco router for configuration and testing, so signal strength is not an issue at this time.

Through the Deco router, I can force a Trackmix camera connection on the 2.4 GHz and 5 GHz frequencies, and therefore I assume the camera is not WiFi 5 (ac) as I understand ac is 5 GHz only. However, I assume the camera could use the WiFi 5 protocol on the 5 GHz and fall back to WiFi 4 (n) on the 2.4 GHz.
As WiFi 4 (n) is both 2.4 GHz and 5 GHz capable, the same as WiFi 6, I am still questioning what protocol is being used by the Reolink camera when the Reolink app connection icons do not indicate that WiFi 6 is active. It would be good to know whether the WiFi 6 feature set can be used on both 2.4 GHz and 5 GHz as my network expands.
I will try to borrow a router that does show the protocol used in the connection.

Updated following further testing:
Using a Verizon CR1000A router, I connected to the Trackmix and viewed the device connection settings on the router.
Connected at 5 GHz the protocol shows as 802.11ax which is WiFi 6.
Connected at 2.4 GHz the protocol shows as blank, so the protocol is indeterminate.
My phone (Galaxy s10+) connected at 5 GHZ shows 802.11ax and at 2.4GHz shows 802.11n (wiFi4).

So at 5 GHz the Trackmix is connecting WiFi 6 but probably not at 2.4 GHz.
It is not clear at the 2.4 MHz connection whether the protocol used is being forced by the router or the camera.

@joseph_1979 I ordered a Trackmix Wifi 6 on December 27, 2024 and received it a few days ago.
How can I verify that it is truly WiFi 6 ?
Other than the order, there is nothing on the camera, the packaging and glossy documentation that indicates it is WiFi 6.
Using the Reolink Android app and PC client app, neither show the WiFi connection icon with the expected 6 as part of the icon.
I also have an E1 Outdoor Pro that does show the WiFi6 icon connection in the same app when viewing both cameras.
I have updated the Trackmix firmware to the latest available on the Reolink download site (v3.0.0.4255_2411271222).