SDDC root password does not allow the below special characters.
&)<)>)')")\)#)=)( and ))[ and ]){ and });):),)/)@) (Note: while sometimes listed as accepted in generic policies, it has caused issues in specific versions and is best avoided for root accounts)`) (also known as a grave accent)
VCF 4.X
VCF 5.X
All the above mentioned characters should be avoided while changing the root password for the SDDC manager.
To change the root password for SDDC manager : How to reset SDDC Manager vcf and root user accounts
It is applicable to all the components of the SDDC manager.