BB is mostly from Russia and Finland. Apparently, Ukraine is no longer run by neo-nazi’s and Russia is bad again. It’s hard to keep up.
I don’t know the what the true cause of the shortage is, but a couple of vendors mentioned geopolitics involving Russia. Another mentioned a slim harvest due to weather in the Baltic region a year or two ago as a potential factor.
In the meantime, I’m finding some BB on FB market place, just haven’t found 1/8” (3mm) in 4x8 yet.