At present we do not send Royal Mail tracking codes to ebay. We have it turned off as an option as it's better for our metrics. However, this means that the tracking is not stored against the order and if a customer requests it, the easiest way to get it is to reprint the label as a pdf.
If you do a reprint after a certain length of time, Linnworks requests a new shipping label instead of reprinting the original. If Linnworks could store the tracking number against the order without submitting it, we could still notify customers and this would solve this problem.
We are talking about Royal Mail delivery confirmation tracking numbers, i.e. RM24 and RM48 service, where the tracking number is not actually traceable through the network. Yeap, I agree submitting it to eBay or any other channel is somewhat counterproductive. We specifically made RM integration with option to ignore this number for exactly this purpose, not to confuse it with actual tracking numbers, I don't think it can be changed easily.
I do however have a workaround for you when you need to retrieve the RM24/RM48 "tracking number".
1) Go to Shipping >Filed Manifests
2) Select OrderId
3) Enter Order Id in the search
4) Open Manifest
here is a bit of retarded UI: It shows 30 items per page, and its not easy to find the exact order id in the list as it can be on the next page. Put the Order id in the Order id filter and then click through pages until it shows up.
I will create a job card for the shipping team to change the UI of this screen.
I myself have requested this too. We have the ability to track those item even if it if RM24 or RM48