Postal Service Frustrations

I have been selling since January and have had no issues with shipping until now. I always send out my packages with my mail carrier - picked up from my house. They usually are scanned that night or the following day.

Earlier this week, I sold two items on Poshmark and one on Mercari. I sent all of them out on the same day. The Mercari item started tracking right away, but the two Poshmark haven’t at all.

One of the poshmark items was with a lithium battery, and I’m wondering if that is why? I labeled it correctly, etc.

I know this falls on me as being ultimately responsible for the shipping and I should take it to the counter at the post office to be scanned in. Just a frustrating way to learn my lesson and wanted to cry about it.