People concentrate on wear levelling and writes wearing out sd far too much whilst possible it is the unlikely cause when a cause that is far more likely is probably to blame. From experience it is usually data corruption from dirty shutdowns when a write is occurring that causes issues. Wipe the sd card clean setup openhab again and use these tweaks to test with and use a UPS to stop power losses from causing reboots. The card will be fine. All flash based storage writes in blocks and the block does not store only the file you are wanting to write to, so this is how a log file write can corrupt an important file in a five second explanation.
