Internal CT failure on Multiplus2

I have recently upgraded my RV to include a Cerbo gxmk2 and noted that I lost the Shore current sense. My tech used the phono plug trick and everything was working fine. Two days later the problem has revisited. I plan the shut everything down and do the phono plug trick again, adding Debrox spray into the receptacle and repeat several times. I would also like to put a little dielectric grease on the plug and run it in and out several times. Is this the proper procedure?

Thanks