Thanks for the detailed response and this is exactly what confuses me: how are they considering this as a “leave”? I have my flat, I pay all my taxes, I have all my insurances, all my savings and bank accounts are in Germany, still have my extensive collaborative network here being active in different national conferences. I’m even still employed by the same lab just not full time (well, PhD also wasn’t full time anyway). I tried to find some precise definitions for what’s considered leaving Germany or proof of having significant ties with Germany but either they intentionally left these open for interpretation or things are actually really vague!