that is not typical. Do you have snails as well?
I think It's fungus from the driftwood.
Have you seen the shrimp or whatever actually in the process of 'pooing'?
If not then I really think it's fungus from the driftwood.
The shrimp will be snacking on it and eventually it will clear up, not harmful at all.
If it's not fungus, then I don't think the shrimp would be producing that much waste, your pleco might be sick.
Is the slime all over the tank, or centralized around the driftwood.
Is the driftwood real, or fake?
And is the driftwood new?
Can we have a 'weirdest thing unintentionally living in my tank' competition?
Lol I think that person in the general freshwater section with the things growing in her cinder block is the winner so far.