Lew's Speed Spool Tournament MB Spool Slipping

I have had my Tournament MB for about 2-3 years now and have had no problems up until this fishing season. I am using 12lb monofilament tied directly through the holes on the spool so the line isn't slipping on the spool itself, and I also have ensured that my drag star is tight and set properly. The issue I am having is that when reeling in my bait and doing "twitching" motions much like you would with a jerk bait my spool seems to "go free" and be able to spin backwards causing large backlashes as the spool spins freely even when the thumb bar is not depressed. The handle itself doesn't seem to be able to turn backwards, and when I try to turn it with my fingers it also doesn't turn freely. This problem seems to happen at random times but seems to be a frequent problem. I clean and oil my reels regularly and this seems to be the only reel that has had this issue. 

The only thing I can think that may be "broken" is my anti reverse bearing, but as mentioned, the handle doesn't seem to be able to turn backwards so I'm a little confused what the issue might be. If you have any suggestions or ideas please let me know.