Why can´t i start a new bounty?

Question

Question:

Why can´t i start a new bounty on the following question: What actions would stop the signal cascades yielding mitochondria growth during basic endurance training??

What i tried / found:

Source: How does the bounty system work?

You must have at least 75 reputation to start a bounty, and at least as much reputation as the bounty amount.

I have 91 reputation.

Source: https://german.stackexchange.com/help/bounty

Users may only have three active bounties at any given time.

No additional bounties open for me.

Questions may only have one active question bounty at any given time.

Not the case.

To avoid overly promotional bounties, if you are offering a bounty on a question that you have already posted an answer to, your minimum spend is 100 reputation (not 50).

Not the case.

Screenshot:

Answer 1

According to the history on the post, you originally offered a bounty on the post on September 25, 2020.

From the meta that you linked:

Why is the system requiring me to choose a bounty amount that's higher than the minimum? For most questions, you can start a minimum bounty of 50 reputation. There are some cases where the system may require a higher amount, though:

If you have already answered the question before, the minimum bounty offer is 100. If you have already offered a bounty on the question before, the minimum offer is double your last offer (see below).

So, while you have the required 75 reputation, doubling the bounty means that you would need at least 100 reputation to offer the bounty (assuming you offered 50 last time).