Resolved: D̶o̶ ̶n̶o̶t̶ ̶u̶s̶e̶ ̶G̶r̶i̶n̶ ̶(̶g̶r̶i̶n̶-̶w̶a̶l̶l̶e̶t̶,̶ ̶G̶r̶i̶n̶+̶+̶,̶ ̶I̶r̶o̶n̶b̶e̶l̶l̶y̶)̶ ̶u̶n̶t̶i̶l̶ ̶f̶u̶r̶t̶h̶e̶r̶ ̶n̶o̶t̶i̶c̶e̶!̶

[Grundkurs]

@oryhp mentioned that with the invalid block inflation could have occured and nobody could tell how many new coins may have entered the system. I guess this is the background for his Bounty suggestion here: Bounty suggestion: Inflation bugs