Hello and welcome to the forum.
I am sorry to hear about the problems you are running into. Does the Syntronik (or SampleTank) standalone load those instruments OK? Do other IK Multimedia instrument plug-ins load their instruments OK in Pro Tools?
As this is primarily a user to user forum, someone-else may chime in [#]. Meanwhile, the best thing to do is raise a
Support Ticket, here for some one to one investigation and help (US (East Coast) Business hours, generally). Response time is usually within 2 working days, but in the current circumstances please allow some more time.
[#] But please remember that the same symptoms do not necessarily mean the same problem.
And, to help others who run into a similar problem, please let us know what you did to resolve the problem.