Completely stuck getting TFTP to work

After banging my head against the wall for two days, I was hoping maybe someone might have a clue for me.

I am trying to set up a TFTP-server, however whatever I do I get the following behaviour:

TFTP server starts and is connectable.

Any file PUT or GET returns:

Error code 1: File not found

Here is some diagnostic data:

sudo cat /etc/default/tftpd-hpa:

# This file is auto-generated by openmediavault (https://www.openmediavault.org)
# WARNING: Do not edit this file, your changes will get lost.
TFTP_USERNAME="tftp"
TFTP_DIRECTORY="/srv/mergerfs/storage/media/tftp/"
TFTP_ADDRESS="0.0.0.0:69"
TFTP_OPTIONS="--secure --blocksize 512 --retransmit 1000000 --create -vvv"

ls -lAh /srv/mergerfs/storage/media/tftp/:

total 0
-rwxrwxrwx+ 1 preben users 0 Jul 18 12:48 test.txt

tftp 10.0.0.10 -c get test.txt:

Error code 1: File not found

ls -lAh .:
total 1.1M
-rwxrwxrwx 1 preben users    0 Jul 18 13:12  newtest.txt

tftp 10.0.0.10 -c put newtest.txt:

Error code 1: File not found

Output from journalctl -u tftpd-hpa.service:

Jul 18 13:12:17 krokodille in.tftpd[77174]: RRQ from 10.0.0.10 filename test.txt
Jul 18 13:12:17 krokodille in.tftpd[77174]: sending NAK (1, File not found) to 10.0.0.10

Jul 18 13:15:16 krokodille in.tftpd[83642]: WRQ from 10.0.0.10 filename newtest.txt
Jul 18 13:15:16 krokodille in.tftpd[83642]: sending NAK (1, File not found) to 10.0.0.10

The file clearly exists in the configured folder, the server is connectable, and the share permissions seem to be OK. Nevertheless, I cannot find the file, and I cannot put files.

Does anyone have any ideas?

Best regards,

Preben

Thanks for trying though:) I've tested some more using dockerized TFTP-servers, but the same error persists. I suspect the server itself is working well enough, but there's something else mucking it up. I did figure out that TFTP seems to use ephemeral ports for the data transfer, so maybe there's something there, however weirdly it doesn't even work using 127.0.0.1.

Finally, success! Ok, so it seems my problem was that my TFTP share was on MergerFS, this does not seem to work. I figured maybe I'd done something wrong with ACL, but after setting every file to 777, and giving ACL access to both the tftp user/group and nobody user/group, it still would not work from MergerFS. Moving the ftfp root to my system drive finally lets me use TFTP:)