I saw a thread about this before, and I though this had been fixed, but apparently not for me. The Marauder progess bar is maxed out and still shows 0/-1 on the display. I have not yet gotten a Marauder DOFF reward, which makes me think it is bugged. Sorry if this is doubling another thread, but I couldn't find one recently.
For the meantime here is a workaround to track your marauding cxp.
Log onto your fed char. Click the xp bar. There should be a window opening with two tabs on top 'starfleet rewards' and 'commendation'. Switch to the commendation tab. Log back onto your kdf char. Click the xp bar again. Et voila!