In a PBEM game of South Pacific Struggle, I got a shiny new Marine Division and moved it up to a Japanese port, with 173 of 210 movement left for all units once the move was completed. I also moved several naval units along with them, and decided to soften the port with air and naval bombardments, first.
To be clear - the Marines were in the same hex as the naval bombardment, but did not participate.
The combat took about a quarter of the turn (six blocks on the turn counter on the side). But now, the naval units all have the level of movement you would expect (147 out of 210), and the marines all have 0 MP!
I am patched up to the latest version (126.96.36.199). This has never happened to me before. Is this a bug?
No. It looks like you messed up when you set up the attack. Notice that the news events from the attack state that the "Empire of Japan successfully defend Verahue." If you were to do a straight bombardment, then there would be a bombardment against the hex, but no news report. You probably selected to attack with all units. As before, any embarked units that unsuccessfully participate in an amphibious invasion have their movement zeroed out for the turn. Since you likely did a minimize loss attack judging from the proportion of MP's left remaining after the initial attack, they would have probably failed their morale checks and failed to advance in.
Since you sent the PBL file, as well as the SAL, I can verify this for you if you PM me the password for your game. Until that point, I'm inclined to say that it is operator error...