derminghsieh, the normal 'timeout' dropout lasts anywhere between six and twenty minutes, and the reason for it is believed to be to determine if there is excessive voltage sag in the pack before continuing with the charging.
I like micarlov's explanations and his creative workaround!
wmcbrine's graph is of a normal condition although in my case I have not seen the gradual and slight power decline as the battery charges (which is logical) and I was surprised that my own TED monitor did not show this.
I have used all of the different ChargePoint public EVSEs (single, double, and CHAdeMO) and have never had any issues with them.
derminghsieh, your curve is normal UNTIL the second drop, and, as you point out, is really weird with repetitive drops at the reduced power level. What device/app are you using to monitor this J1772 input power? I presume that you have no problem L2 charging elsewhere?
derminghsieh, do you have CaniOn to be able to monitor the car's inputs and individual cells? Whereabouts are you located, as maybe one of our forum members with CaniOn could come over and check it out with you?
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV