Facing Issue with slot collection

We have built a use case where user can requests monitors by submitting tickets in ServiceNow directly via MW bot.
Required slots:
Requested_for - User data type

Monitor_type - static resolver

requested_date - string with date validation policy (checking for 4 business days atleast DSL →  

$PARSE_TIME(value, "%Y-%m-%d") >= $TIME().$ADD_DATE(0, 0, IF $INTEGER($TIME().$FORMAT_TIME("%w")) IN [0, 1] THEN 4 ELSE (IF $INTEGER($TIME().$FORMAT_TIME("%w")) == 6 THEN 5 ELSE 6))

delivery_address - String - validation policy DSL →

value.$LENGTH() >= 15 AND value.$MATCH("[0-9]").$LENGTH() > 0 AND value.$MATCH("[a-zA-Z]").$LENGTH() > 0

additional_info: String

Conversational process flow is below → 

Decision policy (mandatory monitor type slot) → if X monitor is selected → call the action activity to submit the ticket in (mandatory all other slots).
 

When we test the plugin, it behaves intermittently and fails while collecting slots. Bot asks the user and the slots are being shown as collected in the logs, in the next step they are shown as missing, and then the plugin fails.

Screenshots attached.

Any help is appreciated.