Bit of a weird one for you. My wife & I this morning tried to queue up for Normal Sanguine Depths & Spires of Ascension, but were blocked from doing so. She is a rogue and is blocked from DPS and I’m blocked from all roles as a Druid. Each of us can queue individually queue for both dungeons, so it isn’t an unlock or gear issue. You may want to double check the blocks you are using.
Wife and I are having the same Issue today (12/02/2020, 17:46 PST). Would LOVE to see a fix on this so we can queue together.
Just wanted to post this link in case it pertained to your issue. If anything you’re all lumped together with that bug. https://us.forums.blizzard.com/en/wow/t/group-finder-cant-queue-for-specific-dungeon/621622