HDMI extension board works with V2 but not V1?

1.Which seller did you purchase the product(s) from?
2.The Model number of the product(s) you have purchased?
B0091 B0031
3.Which Platform are you using the product(s) on?
Raspberry PI Zero
4.Which instruction are you following?
paper instructions
5.Has your product ever worked properly?
HDMI board works with V2 camera, V1 camera works with CSI cable. V1 camera doesn’t work with HDMI board
6.What problems are you experiencing?
I’m trying to use the Arducam HDMI extension board (https://www.arducam.com/product/arducam-csi-hdmi-cable-extension-module-15pin-60mm-fpc-cable-raspberry-pi-camera-specific-pack-2-1-set/) which is advertised as working with both V1 and V2 cameras.

If I use it with an Arducam 8MP V2 camera (CS mount, UC-350, purchased from DLSCorp) the extension board works without a problem.

If I use the same extension board, same CSI cables, same HDMI cable as a Arducam 5MP V1 board (UC-261), the Raspberry Pi fails to detect the camera. I have tried several 5MP boards (identical model) and the behavior is the same. The boards work if they are plugged directly into the PiZero using a CSI cable.

My question is: is this configuration supposed to work, or it the HDMI board known to only be compatible with the V2 camera module (despite the product description)?

Tangentially related: I bought several Arducam HDMI boards for the 12MP HQ camera, and they are working fine without a problem. However I can no longer find this product available - it’s not listed on the Arducam website, and if I click on the Amazon link for my previous orders it takes me to the B0091 "V1/V2 HDMI module). Is this product no longer available? Are you planning to reissue it? I really liked that version of the product because the boards are sized to attach directly to camera module and to the PiZero. With the older board I need to kludge up carrier boards to attach it.
7.What attempts at troubleshooting have you already made?
See description. I’ve tried multiple V1 boards and tested that they work with using a CSI cable
8.How would you like us to help you?
Let me know if this configuration is expected to work, and if so what configuration/cabling changes are required for a V1 vs a v2 board

Followup: I noticed that the description of the board does not list compatibility with the Raspberry Pi Zero.

I tried plugging it into a 3B board and I was able to get it to work with both the V1 and V2 cameras.

Is it expected that the board does not work with V1 cameras and a Pi Zero? If so, I am even more interested in an answer to my question re: the availability of the HQ HDMI board, because I know from experience that that works well with the Pi Zero.