Capital IQ is a legit source, the people who maintain those sites you listed would be better fit to answer your question...
holy hell so we should not trust singaporean government to provide correct information about corporations operating on their soil?
Yes, because we all know how efficient governments are at updating their websites, I'm sure adding ionomy pte info is a top priority. If you really give a shit about the legitimacy of the PTE, call them. I know the people running ionomy and know they have registered, so personally, I could give a rats ass what some shit ran government website states.
But all in all, thank god for all you self appointed super hero's of crypto, keep up the great work, save em all from them crypto scams!