Waht is the minimum free space between GPT partitions?

[Peter]

It appears I can't find an answeer anywhere:

What is the recommendend safety distance (free space) between two
GPT partitions?

I found, if I put partitions directly together (so that another starts
immediately after one ends), under certain circumstances the volumes
become inaccessible and the system (11.2) does crash. Obviousely there
is a safety distance required - but how big should it be?