I have an issue with my listing/FNSKU. Do you think it is a good idea to place the 30% deposit while waiting on the issue to be resolved?

There isn't a wrong answer, because most often creating a listing and placing your deposit happen around the same time.

Often 30% deposits are placed before the FNSKU label is created. However, if you would feel more comfortable waiting until the listing issues are resolved, that is okay.

Sometimes, Amazon may want to see a picture of the product before they reinstate your listing. In this case, you may want to ask your supplier to complete a “Finished Unit” for you to show to Amazon