It seems like that it is all contracts managed by the the Office of Industry Partnerships, within DHS's Science and Technology Directorate, which exists, per its website, to "engage industry and facilitate partnerships with private sector innovators to advance commercial technology solutions that address homeland security challenges."

This is consistent with the explorer having a drop down filter for "Program" with options exactly matching three of the four programs listed as OIP programs o their webpage, excluding "Targeted Broad Agency Announcements”, which from the description OIP participates in but are specifically for some other particular DHS component (which, might handles the actual contracting, which would explain why the data wasn't in the OIP leak, OTOH, the list of current opportunities in that category on the web is empty, so its possible that it is a category that exists in theory but is not actively being used currently.)

This is very much not all DHS contracts, and even the claim that it is "ICE/DHS" contracts seems mostly misleading clickbait trading on the degree of attention to and awareness of ICE even though these contracts are through and for a non-ICE component of DHS.