I just confirm this issue reported on stackoverflow, see below:
debugging - How to debug some complex c++ stls in watches of CodeBlocks? E.G. vector<vector<int> >v - Stack Overflow (https://stackoverflow.com/questions/77758815/how-to-debug-some-complex-c-stls-in-watches-of-codeblocks-e-g-vectorvector)
The OP in StackOverflow started a thread also in our forum (https://forums.next.codeblocks.org/index.php/topic,25656.msg174600.html#msg174600)