New Bash versions prefer for PROMPT_COMMAND to be an array, for example:

PROMPT_COMMAND=(cmd1 cmd2 cmd3)

instead of legacy

PROMPT_COMMAND='cmd1; cmd2; cmd3'

However, zoxide always seems to do something like:

PROMPT_COMMAND="__zoxide_hook;$PROMPT_COMMAND"

which is fine because it works no matter if PROMPT_COMMAND is a regular variable or an array, but if it is an array, it results in an ugly array like so:

$ printf '%s\n' "${PROMPT_COMMAND[@]}"
__zoxide_hook;cmd1
cmd2
cmd3

I suggest detecting if PROMPT_COMMAND has more than 1 array element, and in that case do something like:

PROMPT_COMMAND=(__zoxide_hook "${PROMPT_COMMAND[@]}")

to prepend it to the array nicely.