Hi, I'm trying to change a lutron dumb dimmer switch into a tp-link single pole, no dimmer. I've swapped these out before but have never seen my wiring situation. I have 4 whites tied into some plastic insert "thing" instead of twisting the cap together. I thought I could take one of the whites out and tie it with tp-link but the light flickers on and off when connected. Do I need to connect all five whites together? Those plastic things are a pain to remove the wires to try and twist. Do they sell the plastic thing to accept 5 inputs? Thanks!