Temperamental SIM sensing microswitch? Admittedly I've only had about 10 phones since my first one some 20 years ago (including models I tried for a few days and didn't like; I tend to look after my things and use the ones I like for years rather than change them with fashion), but I have NEVER even heard about any such thing. Admittedly most phones need to remove the battery to replace the SIM, so sensing the card is part of the boot sequence, but there was one remarkable exception: Palm Treo 600 with a hotswappable SIM. Served me without a fail for 9 years. Cost new about a half of new Jolla.