The steel (not pot metal) handle is induction brazed to the tubular bolt body. Over many years of gunsmithing, I've seen a few that were detached. On a very few, it was obvious that there was way less than 100% contact. Usually brute force was used. BFH, large rock, etc. applied to bolt handle. Handles peeled off, bending in the process. Sometimes broken. I have also seen Mauser handles snapped off by the application of the same sort of excessive force.
Get the rifle to an authorized Remington service center. They will likely replace the bolt. No, they won't sell you a bolt.
I have successfully reattached them using fluxed paste silver braze. It is essential to use a good jig to hold the handle in exactly the correct position, along with a heat sink and anti-scale compound. Red heat is involved, there is cleanup and polishing afterwards. My current M700 .30-06 has a barrel from one rifle, receiver from another, stock from a third. The bolt body is from a fourth, obtained without a handle. I used a universal handle, cutting the extraction camming surfaces. Silver brazed on. Probably the only 700 in captivity with a Ruger pattern bolt handle.
I have heard of TIG welding being used, but I don't TIG weld.
If you have lost faith in Remington, I'll buy the remains as is, for a salvage price...