All of my Google Merchant Center items have been suspended due to inaccurate shipping costs. I asked for Google's supports help, but they can't solve it.
The issue is quite complicated: my store's shipping rate is calculated based on products' weight plus the package material's weight.
Package Weight: 30g
Product A Weight: 50g
Product B Weight: 90g
Shipping rate for product A: 50g+30g=80g= $3.8
Shipping rate for product B: 90g+30g=120g= $5.2
In this case, once I put $3.80 on the shipping rate for 0-100g in the Google Merchant Center, there will be no problem when a customer orders a product for lighter than 70g; the shipping rate on the landing page will match with the shipping rate in the data feed. However, these two shipping values do not match when a customer orders a product within 71-100g, it will jump to the second tier.
It's no way to add the package material weight into all products since it will overcharge when a customer buys more than one product. How can I solve this problem, any suggestions?
If the shipping rate is different for 71-100g, then add the shipping rate for this weight range.
My recommendation is to setup the rules in Google Merchant Center to replicate how Shopify calculates your shipping prices.
Alternatively, the only way to resolve this is to overestimate.
Alternatively, rethink how you calculate shipping and make it simpler.