We have dealt quite a bit with Tequipment over the years and everything we received from them has been factory-sealed (as far as it's possible to tell, anyway). This is one of the reasons we order from them. Personally, I don't want _anyone_ mucking around with equipment before we get it, other than, possibly, a factory-authorized service center, and in that case, it had better be for a very good reason. We've had issues in the past with equipment that had clearly been re-packaged after leaving the factory.
In fact, we recently ordered a Siglent SSA3021X Plus directly from Siglent, because they had a special deal, and we thought they would surely be sending us a "fresh" instrument that had not been molested in any way. Unfortunately, when we received it, it was clear that it had been opened after leaving the factory. There was double tape, and the first layer had been cut, there was no screen protector, and it didn't have that "factory-fresh" smell of lovely out-gassing plastics and fresh solder, haha.
But this came directly from Siglent, so surely it would be a perfect instrument, right? Nope! The front end on this thing was all but dead, and it was almost impossible to see any trace of a signal on it. (We have a number of Siglent SSA's, so it's not like these instruments are new to us.)
Thankfully, Siglent was very apologetic, and immediately set up an exchange -- even sending out a "new" one before we had sent the original one back. They did open the box on the replacement unit, after asking our permission, to take out the user manual and power cord so that we didn't have to send those back, but assured us it was a brand-new instrument.
When we received it, the replacement unit did have a screen protector (which was a major pain to remove, by the way, leaving a residue all over the screen that had to be cleaned off, but at least it was there), and even smelled factory-fresh, ahhhh.
So, if it were me, I would definitely return it for either a replacement or refund. Time is money, and what if there’s something wrong that you aren’t able to identify until you’re in the heat of a deadline and then discover an issue?
A number of years ago we had to return a brand new instrument to Tequipment that, though received in fresh packaging and working properly, didn't perform one of the analysis functions we required. The data sheet for this instrument didn't mention this limitation, and Tequipment let us purchase the next model up the line, and told us they'd be selling the returned one as an "open box" unit. Sure enough, that instrument did show up as an open box item at a reduced price -- as is the proper way to do business. There are a number of reasons “open box” sales exist!
Best of luck to you, and I hope any of this helps anyone dealing with similar situations.