I neglected to add this detail. It has been formatted by the Lineage device, but the issue persists.

When I get an SD card with intent to use in a phone, I will let that phone format it first to be sure it's compatible with at whatever format it wants to work with. The computer will certainly be able to read whatever format Android chooses.

Short answer, just let the phone "fix" it.

I just tried something cool. I installed Round Sync app (from f-droid) on device A, as a wrapper for rclone (basically rsync on steroids with cloud/non-cloud remotes easy to add). On android device B I turned on the simple FTP server included in Material Files (feel free to pick a different server or protocol)

Both devices on the same wifi; on devA in RoundSync I added the FTP remote, then created a task to copy local to remote (you can also sync, local to remote or vice-versa). It let me pick a folder from internal storage to send to a specific destination (could even create new folders while browsing the remote).

Started the task, it copied all perfectly (it's rsync). I also re-started the task and it correctly scanned the remote and reported success (instead of duplicating). So all smooth! :) I'm sure one could rclone via termux or something but an app is way more convenient for most.

There's also https://github.com/9001/copyparty if you just need to one time transfer files quickly

You use Termux and Termux:API to host, or copyparty Up! app to send to a computer running Copyparty

The SD card going read only suggests to me either the sd card is dying, or its a fake SD card. There is a scam where for example, bad sellers will sell a hacked 32GB sd card and list it as 64GB and it shows up as 64GB in your device, but when you write more than 32GB to it, it just starts from the beginning of the SD card storage addresses, and overwrites the original files on the device. The end result is, the original 0-32GB is overwritten erased, as it writes the next 32GB of the '64GB' faked total.

If you have the storage space available without the SD card on the new device, I would maybe use syncthing app to transfer the files locally on your own network, from old device to new. If you're handy with linux terminal commands, you could also maybe use rsync to copy the files over your network as well.