Sendle are - by all accounts - fantastic....until there's a problem, then they are absolutely terrible.
If it was an ATL drop-off / safedrop, this status should be reflected properly. If it's standard practice under current circumstances, then there should be a way to differentiate between "signed for by recipient" and "droppped off at premises" - a logistics company, which all courier services / brokers are, should have this as standard, and the practice of the delivery driver signing the recipient's name is questionable, to say the least. Regardless of what actually happened, this creates a false record of events.
It also sounds like no proper investigation was carried out, if they at first insisted you'd signed for it, and then came back to say it was droppped off somewhere else a couple of weeks later - this is exactly the kind of problem caused by creating fasle delivery records!
Personally I would never ship with them, or (knowingly) buy from a seller using them, as Sendle's customer service leaves an extreme amount to be desired. Issues can happen with any business, but it's how a business deals with those issues that distinguish them as a good or bad company to deal with - a friend of mine experienced something similar to you, in that a package said delivered but no package in sight (they were home all day). When they contacted Sendle about it, they were told that it's delivered as far as they were concerned, but they couldn't say where or who to, and that Sendle's TOS allow the drivers to deliver packages to neighbours if they can't access the recipient's property. They didn't even say that's what happened, just threw it in there as a possibility, and of course that meant they didn't provide any usable info as to where or to whom the package had been delivered.
To answer the question, though, no, it is not a "normal" thing to do in the sense that it's ok, though anecdotally it happens with every delivery service here and there.
