rdweb authentication error 0x607

Hi,

I deployed a RDS 2012r2 with a self-singed certificate and everything worked until I changed the certificate with a third party cert.
I can still login using RDP from a client through RDS Gateway and broker .. is working, but when I try to log on through RDWeb I get the famous "authentication error 0x607" error.
Setting/changing the collection security to low ... is not working for me.I can't imaging that recreating the collection is the only solution to this.

Thank You,
Best Regards,

MrFormula