Cannot pass this challenge although I have passed it on another account.

I've completely recreated every step. The Home page is Process_Automation_Home for developer name. This challenge keeps telling me it cannot find the new lead flow even though I can use the flow on the page to generate a new lead. It has full functionality but apparently theres a magical parameter I can't seem to pass to complete this challenge.

Hi all, I am so close to finishing this process automation badge but am stuck in one area in Step 7.

I've built out my process builder as follows





And my date formula as follows
 

Case(MOD(Date__c-DATE(1900,1,7),7),0,"Sunday",1,"Monday",2,"Tuesday",3,"Wednesday",4,"Thursday",5, "Friday",6,"Saturday", "")

 

Challenge Not yet complete... here's what's wrong:  The Robot Setup Day of the Week formula does not seem to be working properly. The Day of the Week should not fall on Saturday or Sunday. 

It works nicely but doesn't seem to pass, what could be up.
 

Your company sells cylindrical hyperbaric chambers. You need a formula field that calculates the volume of a cylinder for you, rounded to the nearest whole number, given its radius and height. Use the existing mathematical formula for the volume of a cylinder, V = πr2h, where r is the radius of the cylinder, h is the height, and π is the constant Pi. Note: Although this formula field might best be created on a custom object, for simplicity, we’ll create this formula on the Opportunity object.
>Create 2 custom fields of type Number on the Opportunity object: ‘radius’ with a resulting API name of ‘radius__c’ and ‘height’ with a resulting API name of ‘height__c’.
>The formula should be named ‘Cylinder Volume’, with the resulting API name ‘Cylinder_Volume__c‘ and should be created on the Opportunity object.
>The formula should reference the custom fields ‘radius__c‘ and ‘height__c‘.
>The formula should use 3.14159 as an approximation of Pi.

Heres the challenge that im stuck on. i have created the 2 custom fields. What im stuck on is where do we create the formula. Do we put it in the custom fields or is there another place u insert it?

thanks if anyone can help
 

I am getting error message while solving this challenge in Trailhead :

To complete this challenge, add a validation rule which will block the insertion of a contact if the contact is related to an account and has a mailing postal code (which has the API Name MailingPostalCode) different from the account's shipping postal code (which has the API Name ShippingPostalCode).Name the validation rule 'Contact must be in Account ZIP Code'.
A contact with a MailingPostalCode that has an account and does not match the associated Account ShippingPostalCode should return with a validation error and not be inserted.
The validation rule should ONLY apply to contact records with an associated account. Contact records with no associated parent account can be added with any MailingPostalCode value. (Hint: you can use the ISBLANK function for this check)

Error Message is :  There was an unhandled exception. Please reference ID: HKIZNLVZ. Error: Trailhead::TrailheadTimeOut. Message: Trailhead.view: failed to get a 200 response. Made 3 attempts each resulting in a 403 or 500 failure for url challenges?key=%5B%22trailhead.challenge.validation_rules.en.us.192%22%5D.

I am not sure what went wrong here.
My Validation Rule is on Contact Object  :

  AND ( NOT(ISBLANK( Account.Name)),
( MailingPostalCode <> Account.ShippingPostalCode))

Can anyone please help with this.