Since I have both $GLAD Gladstone Capital and $SOLV WI (+0 %) Solventum as a 3M spin off in my Scalable portfolio, I asked Gettex today when to expect the new shares to trade. Here is the answer:

"there is no settlement confirmation from the German central securities depository Clearstream for either share.

No orderly stock exchange trading is possible without a valid settlement confirmation.

The resumption of trading in Gladstone Capital or the inclusion of Solventum in trading is not possible under these circumstances."

If SC can't manage it with Solventum, there is always the detour via a securities account transfer. I'm not so sure about Gladstone because I still have the old ISIN in my securities account before the reverse split and not the new one. I don't even know whether the old share can still be transferred. I've already had a "normal" share split at ING, but that went without any problems. A reverse split shouldn't be rocket science either.

I'll just have to be patient now. At the moment, I can't imagine that the money will simply disappear at some point.