Spotting

It's an amblypygi of family Phrynidae. From armature of palps i agree it indeed looks to be Phrynus sp. The dominant one from this zone is P.whitei. But here the supposed 'diagnostic' reddish/white marks on carapace are really faint, so less certain on the species. In Nicaragua it's sympatric with P.maesi, so multiple species can coexist.

Perhaps this genus? https://en.wikipedia.org/wiki/Phrynus

This looks like a tail-less whipscorpion Damon diadema... but those are in Africa. Is this captive?