The brand new 377/2 has no problems with the gangway, you probably mean the 377/4. I haven't read any reports about the broken gangway of the 377/4 for a long time and therefore assume that it has already been fixed.
377/2 is not formation designer friendly - you can only use standard 4 coach formation, not individual coaches 377/4 still has gangway glitches when used in unusual (unusual for 377/4 variant) formations