Cannot use IOS Files app to copy from a read only external device.

I am trying to copy files from an SD card into a folder on my iPhone. I’m only doing this in order to then use Files to copy from that folder onto a different SD card. (I want to be able to do this because on a planned trip I will only have my camera and my iPhone and no internet connection and I want to make a backup of my photos. I also can’t go through Photos - the app - because of the odd way it handles RAW + JPEG files, but that’s a different issue. I’m using an i0Phone 11 running IOS 16.2

I can insert the SD card either directly into the Lightning SD reader, or indirectly through the Lightning to USB 3 dongle and a USB card reader. Both show the same effect. I can navigate to my files on the SD card and select them. I can then hit the folder icon at the bottom of the screen and copy the selected files to a folder I’ve set up on the IPhone itself for this purpose. That all works fine.

BUT I can’t do this if I’ve clicked the SD card to write protect! If the external device is read only, Files greys out that folder icon and I’m stuck. And since the whole object of the exercise is to make a backup of these photos, I’m not going to risk putting in a write-enabled card!

I suspect iPhone developers don’t see many write protected devices nowadays, and as a result this is just a bug that shows up in this unusual(?) scenario.

I do have a workaround, by the way, that involves using separate cards for RAW and JPEG, which my camera lets me do, and then I can go through Photos without any problems. So really I’m just posting this here to ask if this is really a bug I should report to Apple, or if I’m just missing something obvious. (I also know lots of people think using RAW+JPEG is misguided anyway, but that isn’t the point here. )