time machine usb drive is fine locally but not detected over wireless router tp-link AX3000

Sorry, but I'm not clear on what you are trying to say.

Are you saying that Time Machine works OK when a USB drive is connected directly to your Mac, but Time Machine does not work when you connect the same USB drive to the USB port on your TP-Link router?

If not, please provide more details.

It might help if we knew how the USB drive is currently formatted. If you are not sure how to check this, post back for instructions.

Very few routers will support Time Machine backups to the USB port on a router. The only routers that I know of that are compatible with Time Machine are the Synology router and some of the upper end Asus routers.

TP-Link claims that their router will support Time Machine and they provide the two support articles below regarding this.

https://www.tp-link.com/us/support/faq/1564/

https://www.tp-link.com/us/support/faq/2729/

If these articles from TP-Link do not do what TP-Link claims they will do, there is nothing that Apple or we can do to help.

precisely. talked with tp-link tech support but they gave up on me in saying tm is Apple's product.

TM is Apple software. But TP-Link Support Articles claim that their router will support Time Machine. It's up to TP-Link to make good on their claims.

We still don't know how the USB drive has been formatted, but if it is APFS, I am sure that TP-Link routers cannot support this format. Neither can Synolgy or Asus. You have to format the USB drive as Mac OS Extended (Journaled) to have any chance at compatibility.

Do you know how the hard drive is formatted?

Good luck! Would be very interested in your results. Let us know when you can.

Any luck?

Thanks!