BMW Repair: E46 B20 low compression, camshaft timing, valve lifters

Question
I removed the engine of a friend's 2.0 2005 E46 4-cyliner
B20 Engine to replace leaking seals - crank oil seals, oil
pan gasket etc. When refitted the engine turns slowly. Had
jumped the battery still the same. Checked the compression
and they are low across all cylinders (about 60psi only).
Only the 2nd cylinder has 110psi. I forgot to remove the
fuel pump fuse when checking compression so this could be
the reason for low compression readings. What should I do
now? The fuel and fire are fine. The engine was left
sitting for about a month before being restarted. What
could be the problem? Stuck valve lifters? Thank you in
advance.

Answer
From your note, I'm assuming you didn't change anything that required distrubing the camshaft/crankshaft timing or camshaft/camshaft timing.  If you did, I'd start there.

Lifters shouldn't stick after a month, and engine should have been very noisy if that was the issue.