OK, fixed it. Card was in correctly, it even made an audible "click" when card was pressed in. I released it by gently wiggling each end of the card with a sharp needle; the card gradually came out far enough to grab it.
Other cards still work fine so the jammed card must have some defect, but it looks just fine.
Thanks for the advice.
Some times the thumb/finger nail just will not do it. It is necessary to use a tool of some sort tweezers or small tip screw driver just to give that extra little push. Only problem with that extra little shove is the SD-Card sometimes is ejected quite fast and results in it flying across the room. The device powered on or off will not stop you removing the SD-card but you are likely to corrupt the card and loss items on it and the card will probably require formatting losing everything of the card. But then you may be lucky and have no problems, it's luck of the draw.
I have two identical cams. With one the SD card inserts and ejects normally, but the other requires the card be pushed further in to eject and then you need something small and pointy to ease it out fully. I ruined a 64GB card in that second cam trying to pry the card out; the outer end of the card folded over and broke off. Patience and care are needed with SD cards!
It's been years since I've had to "click" to inset or remove the card from my dashcan and I remove it everyday to archive the files. I just add a small piece of tape folded over the back edge of the card as a pull tab and just pull to take it out.