write_fulfillments app scope update on existing stores not working

[Samon]

I have an app with some scopes and need to add the write_fulfillments

 scope on already installed app without asking the store owners to uninstall and reinstall.

Have constructed the below url referring to guidance here,  

```

https://<store>.myshopify.com/admin/oauth/authorize?client_id=<clientId>&scope=write_fulfillments&redirect_uri=<redi_uri>

```

and getting failure response as 

```

{"message":"1 validation error detected: Value null at 'state' failed to satisfy constraint: Member must not be null"}

```

then I added the state and got the following failure response : 

```

{"message":"Requester does not have a valid state to complete OAuth"}

```

-----------

Did the same experiment on multiple other scopes like write_third_party_fulfillment_orders and was successful redirected to the consent page (without the state in the URL).

Questions : 

1. Why is the url not redirecting for `write_fulfillments` scope while it is working for many other scopes like write_inventory, write_products, write_shipping, write_third_party_fulfillment_orders

2. Why is url with `write_fulfillments` scope required to have a non null state ? while others didn't require it.

I see there are some known issues (Ref) when updating the `FulfillmentOrder` scopes but does it also impact write_fulfillments scope ? and what is the workaround for it ? 

3. If state is mandatory for some reason for `write_fulfillments` scope addition how can i get the value of the state if i am generating the url outside of my app code.

I intend to email these reauth URLs to store owners so that they can get the write_fulfillments scope added. Please let me know if I am missing something.

Regards