Solid layer of funky something on top

I noticed as the fermentation approached complete there was a layer on top that seemed somewhat solid. I cold crashed and it dropped out but when I racked to kegs tonight I could see in the fermenter that the plug dropped as a unit. I've never seen this before and the beer attenuated to 1.005 which is at least a couple points lower than I expected. The beer taste fine as far as I can tell and I don't notice any weird aroma but I thought I remembered hearing this was a characteristic of a soured fermentation or infection.

Yes...No?

Can't say if it's infected, but if it tastes good, personally, I would drink the hell out of it.

Brew on my friend

I'm sure planning to drink it!

Just wondering if the membrane is a common occurrence or if it is usually linked to bret or something?

We would need pics to evaluate it. Had you ever used the particular yeast strain before? If it starts to turn on you, drink fast while it's still enjoyable.