Struggling with Dude on hEX RB750gr3....

I’ve followed the wiki page here https://wiki.mikrotik.com/wiki/Manual:The_Dude_v6/The_Dude_server_on_hEX_RB750Gr3 to set the dude to store its database on the SD card, but after rebooting the router 1 of 2 things happen, If I use exactly the same folder name of “disk1/dude-data” then i’ll continually get something along the lines of “could not read data folder” (I don’t recall the exact message) and if I open the files list in winbox I only see the disk1 folder but no dude files at all underneath
Or if I use the folder “microsd” then upon reboot almost everything is missing from the dude, all the images etc, only the database file is present

So can someone shed some light on this? I’ve tried uninstalling and reinstalling the dude package 3 times, reformatting the microSD card as many times, tried various different folders. The only structure that properly works is using flash, but then after a reboot the database is completely wiped so its no good for me at all…
This HEX router is in an environment that will experience frequent power loss and needs to come back online. It will generally have a fixed database that very rarely changes, but when its set it has to be reliable where it can lose power, restarts again and all should just work as it was before

I believe the problem was with the microsd card, replaced it (kingston) with a Sandisk ultra and everything worked. The kingston seemed to store files ok but who knows, either way if anyone has such a problem in the future try replacing the microsd card with a known working one - or do a full diagnostic on it to make sure it has no bad segments