Shipping anomaly

Hi there,

We’ve been using woocommerce for a few years with a small online shop.
I’ve noticed a problem with shipping & paypal that occurs sometimes for no apparent reason.
The problem is that the order on paypal does not have any shipping cost, but the order in Woocommerce does. The paypal order is charged at the lower cost & the woocommerce order is on hold showing the error. We just take the hit & ship it anyway, but I can’t see why this would happen.

Our shop uses 4 shipping zones (north, middle, south, islands) for the country.
Each zone has a single flat rate, except the islands which have 2 flat rates.
Every order (north, middle, south) has the shipping cost IN PAYPAL listed as part of the products bought. (as if shipping was a product)
– Item 1
– Item 2
– Shipping
& the actual order shipping in the totals on paypal says 0

But the when one of the flat rates for the islands zone is selected, instead it shows in paypal in the order grand totals under the dedicated shipping line.

I don’t care which way round it does it or displays it, but there seems no logical reason why it would do both ways, I have no way to affect that in woocommerce its just a simple flat rate with not really any options.
The only thing I care about is why sometimes, very rarely, it doesn’t have any shipping at all in paypal.

Seems like a bug – do you know what’s going on?

Woocommerce 3.2.0 / WordPress 5.4