Link file to create a second video channel

(NOTE 1: I have a few related questions/issues that I'll describe in detail, but I'll lead with a simplified question. )

QUESTION: How do you a link video to create a second video channel when there is already a video linked to Video Channel 1?

SETUP
RC Version: iOS 7.5.2
Phone: iPhone 11 Pro - iOS 15.5
Cameras:
- Channel 1 (used for PIP): iPhone selfie cam
- Channel 2 (front-facing): GoPro Hero 7 Black

CURRENT SITUATION AND BEHAVIOR OBSERVED
1 - The video from my iPhone Selfie camera is linked correctly on Video Channel 1
2 - No other videos are currently linked to the session.
3 - I have uploaded the session's GoPro videos (3 chapters) and they are in "App Storage"
4 - When I click the "3 dots" menu on the (first chapter) GoPro video, the only link option is "Link after" (other options are: "Move to Photos app", "Rename", and "Delete").
5 - If I click "Link after," it gives me the options to either: 1) select the video (iPhone selfie) that's linked on Video Channel 1, or 2) cancel.
6 - If I select the the existing video it (not surprisingly) puts the GoPro video on Video Channel 1 (after the existing video).
7 - If I then change the channel on the newly linked (GoPro) video (by clicking the encircled channel number and selecting a different channel), it changes the channel for both videos and the GoPro video remains sequenced after the selfie video.

DESIRED BEHAVIOR
I want to create a second video channel, and link the 3 GoPro chapter videos sequentially to that channel.


(NOTE 2: Following is more info on how I got to this point--it's similar to the behavior discussed in: https://racechrono.com/forum/discussion/comment/11803. I'm including for your information. While, I'm interested to understand better, I have worked around the issue.)

HOW I GOT HERE
1 - I recorded a 25 min session using the setup described above. This was my 6th such session of the weekend, and I've used the same setup on many occasions without encountering the issue I'm about to describe
2 - As mentioned above, the iPhone (single chapter) selfie video was automatically linked correctly to the session on Video Channel 1.
3 - Consistent with usual behavior, there was a "Unknown name" video for the GoPro video on Video Channel 2 and the instruction "Connect camera to resolve file name."
4 - As usual, I connected to the GoPro via the GoPro WiFi and then clicked connect camera.
5 - *Unlike normal behavior*, the image area for the video remained gray with the words "Connected to camera" (I think). Normally at this point the unknown name is replaced with the actual file name, an image from the video is displayed, additional chapter files (if any) are added, and linked in sequence.
6 - I then manually uploaded the GoPro files I wanted from the "Camera Storage dropdown."
7 - All files correctly appeared in the "App Storage" drop down.
8 - I clicked the context menu on the first GoPro chapter file, and selected the option to link it after the placeholder file.
9 - I had hoped that doing so would remove the placeholder file, but it remained in place with the GoPro file linked after it.
10- I then deleted the placeholder file (hoping that the GoPro video would remain and be the first and only file on Video Channel 2. However, both files were unlinked from the session. This left me with no files linked to Video Channel 2 (and the selfie file still linked correctly to Video Channel 1.)
11- This is the current state which is described above.
12- As a final note, I'll add that I encountered this same issue on my 7th and final session of the weekend. I estimate that I've run this same setup (spanning various RC and iOS versions) on at least 50 consecutive sessions and have not encountered this issue until now.

Thanks in advance for your guidance!

-- John