What is the LNBF ? It will have to be a DP Dual, to feed the DPP44. If it is a legacy, that is your problem.
There is no problem feeding signals (82) from a DP Dual LNBF into just 1 port of a DPP44 Switch, the DPP Seperator will also be fine.
Do NOT use a splitter, you have all you need with...