Hi,
I have created a validation rule with 4 conditions:  If the lead status reaches stage 5 SQL, then I want to make sure the picklist fields Platform Type (Platform_Type__c) and Platform Sub-type ( Platform_Sub_Type__c) have picklist selections, as well as the rich text field Company Description ( Organization__c) has company information in the field.   I wrote this data validation rule:

And(ISPICKVAL( Status ,"5-SQL"), 
Or( 
ISBLANK(Organization__c),ISPICKVAL( Platform_Type__c,""), ISPICKVAL( Platform_Sub_Type__c,"") 
))

I have tested the rule on the picklist values and it is working correctly.   However, on the rich text field, the rule is being skipped and not working so I can save the lead as a Lead Status "5-SQL" with the company description having no data in the field.  Can anyone explain why this validation rule is skipping the ISBLANK logic?

Thank you in advance for your help.   I very much appreciate your advice.
Thank you!!!