Since even that tool does not have a selective temperature monitoring I assume there is really no way to look at core temperatures separately, right?!
(Hoped speccy has this like it had for my Intel setup)
im not too sure if it's possible to monitor individual core temps of ryzen
i think it just reports the hottest part of the die, not necessarily core
maybe try HWinfo, i never use it personally but it's widely recommended around here
and welcome to the forum! remember to quote when replying so people will see it