I have read a LOT of threads about third party batteries for Fuji cameras, but I have never seen anyone suggest they might cause problems like you describe. However, I know nothing about Panasonic cameras, so there may be issues I am unaware of. If the batteries were mine, I'd want to check the voltages with a multimeter.
By "update" I assume you are trying to update the camera firmware?
With Fuji cameras, I believe it is possible to apply a firmware update without first loading the firmware to an SD card, either by USB cable or maybe wirelessly, using an app -- I don't really know the specifics, because I have always updated my Fujis from an SD card.
I am somewhat skeptical that updating your camera firmware is going to solve your Playback problem. I still think the reason you cannot preview your photos in camera is more likely due to either:
- a corrupt or improperly formatted card, or
- a card type or size which is incompatable with your camera, or
- a hardware problem with the card reader in your camera
... but I guess it could be a problem with the camera's firmware, so you can try that.
Have you tried the suggestions by
@loccdor to verify what SD card specifications are recommended by Panasonic -- and to clean the contacts on the SD cards?