welcome to the forum,
on a mount, those do nothing.
as mentioned, first run rclone selfupdate and test again
if the issue persists, then run a test using the simplest command possible
in most cases, the vfs file cache is not required.
so as a test, run this and see what happens
rclone mount /mnt/ltfs /mnt/ltfs_cache --allow-other --read-only -vv
check out my summary of the two vfs caches