Please describe the problem.

if remote path has some folder name starting with # (may be also anywhere, didn't check) -- annex fails to discover UUID

#!/bin/bash
set -eux

cd "$(mktemp -d ${TMPDIR:-/tmp}/dl-XXXXXXX)"

pwd=$(pwd)
(
mkdir repo
cd repo
git init
git annex init

echo text1 > text
git annex add text
git commit -m 'initial small'
)

for d in 'clone1' '#clone2'; do
    (
    mkdir "$d"
    cd "$d"
    git init
    git annex init
    )

    r="${d//#/}" 
    (
    cd repo
    git remote add "$r" localhost:"$pwd/$d"
    git annex sync
    echo -n "!!!! Remote $d. annex uuid: " 
    git config "remote.$r.annex-uuid"
    )
done 

which shows

+ git remote add clone2 localhost:/home/yoh/.tmp/dl-nD3k2cN/#clone2
+ git annex sync

  Unable to parse git config from clone2

  Remote clone2 does not have git-annex installed; setting annex-ignore

  This could be a problem with the git-annex installation on the remote. Please make sure that git-annex-shell is available in PATH when you ssh into the remote. Once you have fixed the git-annex installation, run: git annex enableremote clone2
...
!!!! Remote #clone2. annex uuid: + git config remote.clone2.annex-uuid

What version of git-annex are you using? On what operating system?

Originally was a bit older, now tried with bleeding edge

❯ git annex version
git-annex version: 10.20250828+git47-gab9bbeabd5-1~ndall+1

FTR: I was trying to backup some old behavioral videos (octopus) from the laptop under #video folder which was reproduced on remote end as well.