Before Excalibur, the last time Rictor and Shatterstar interacted was during the Shatterstar miniseries. They were on the rocks in that series because Shatterstar was having trouble coping with not living in Mojoworld and adjusting to life. Shatterstar had started an apartment complex that rented to people who were castaways/runaways/etc. of odd alternate universes. By the end of the mini they had gotten back together after Shatterstar's love and connection to Rictor let him jump across all of space and time to get home.
Everything else, including Rictor suddenly having trouble with his powers, was invented for this series. Last we saw them they were happy and together and running that apartment complex with all of the rescued tenants.