Are the Finisar SFPs compatible with the 10Gtek FMCs? Looks like 10Gtek is Cisco compatible. Finisar isn't compatible with Cisco, though, so that may be the issue. I don't think 10Gtek is compatible with both Cisco and Finisar.
Someone with more knowledge will hopefully provide a suggestion in regards to the FMCs. Ironically, I did a deep dive on optical last night. I found threads from WhatsBestForum (here, here, and here) pretty helpful, as well as some from Audiophile Style.
I think the question I have as a follow-up for the community is whether or not that "active" optical cable may also be causing an issue - I candidly don’t know, but I vaguely remember reading this as an issue in one of the threads above.
Like you, I’m still learning while regurgitating some of the information I had been reading last night. I'm pretty confident more members will contribute to help figure this out. As a side note, I've found one of the easier paths is looking at Small Green Computer's solutions, which can be found here and here.
I would have stuck with something simpler, that has the media converter built in. Keep in mind that 100 MBits is overkill for any streaming of audio or video. 1 Gbit (1000 Mbits) is overkill x 10.
A 192k/24 bit stereo signal is barley 10 Mbits. A 4K video stream requires around 50 Mbits or less, depending.
So, a 1 Gbit/s cable can carry 20 4k video streams at once.
Maybe that can help you pick out a better integrated adapter and cable such as: