Need config suggestions on new Comcast cable box with TiVo Humax Series2 DRT400

I want to thank the community in advance for answering my question. And if I've posted in the wrong forum, my apologies and let me know where to post. Thanks.

Sony Bravio XBR
Humax TiVo DRT400 - Series 2
Slingbox 500
Motorola DCT2000 <-- This is the problematic Comcast/Xfinity cable box

Yesterday afternoon, I encountered a snowy picture screen. Yes ... I did the do-diligence (i.e using Chromecast to project HBO Go onto the TV - worked okay!, checking cables, rebooting devices,...

Need config suggestions on new Comcast cable box with TiVo Humax Series2 DRT400

Need config suggestions on new Comcast cable box with TiVo Humax Series2 DRT400