Well this was happening to me consistently and this is how I fixed it. I mounted the SAMBA logfiles share and found this gem:
Quote@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: UNPROTECTED PRIVATE KEY FILE! @@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0620 for '/storage/.cache/ssh/ssh_host_rsa_key' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
1. I shut down the rpi400 and yanked the sd card
2. I inserted the SD Card into my iMac running fedora
3. nothing happened
4. commence searching!
5. running `lspci` I discovered with some chagrin that I owned a Broadcom BCM57765/57785 SDXC/MMC Card Reader
6. I ran these commands to mount my wicked high speed sd card as just-sort-highish speed
A quick reinsertion of the card sufficed. With the SD card mounted I `cd`'d to libreelec's /storage/.cache/ssh and did a
That having been accomplished, I reinserted the card and rebooted, and hey presto, ssh works again, I no longer need to mount the farkakte smb shares.