1. Physical dongle tends to break, and when it does, they expect us to give them replacing parts
2. They do expect bug fixes-- especially calculation bug fixes-- as the bugs are discovered. It's hard to leave their production critical apps broken like that once you know that the bugs can cause monetary or even life loss.
Maybe I'm the weird one to expect reasonably bug-free software, and if a bug is found, an eventual bugfix "for free"? ESPECIALLY if they cause monetary or life loss!
A bug means the developer did not do their job. Let's not pretend this is OK.
But the actual dongle... look, something like that should have a 30+ year warranty. There should be a plan for how to replace it a couple times before making the initial sale.