Getting sense stems for nltk semcor corpus words

I was trying semcor corpus in nltk.

I found this code here:

>>> list(map(str, semcor.tagged_chunks(tag='both')[:3])) 
['(DT The)', "(Lemma('group.n.01.group') (NE (NNP Fulton County Grand Jury)))", "(Lemma('state.v.01.say') (VB said))"]

I tried the same on colab (check last cell in this notebook):

>>> list(map(str, semcor.tagged_chunks(tag='both')[:3]))
['(DT The)',
 '(group.n.01 (NE (NNP Fulton County Grand Jury)))',
 '(say.v.01 (VB said))']

Here is the screenshot from colab:

The problem

Note that on nltk page, for Fulton County Grand Jury output is given as Lemma('group.n.01.group'), but on colab, I am getting group.n.01. So I am not getting sense / synset lemma.

• In group.n.01.group
  • first group is a "stem for sense word"
  • last group is "stem for input"
• In group.n.01
  • (first and only) group is "stem for input"
  • no "stem for sense word" is returned

Weird thing is that it was giving me correct output yesterday. This notebook will clear the doubt as it has same two lines executed today and yesterday. Yesterday (2/9/2021), I was getting tags in format group.n.01.group, but today I am getting tags in group.n.01 format (NOTICE RED AND BLUE COMMENTS):

What I am missing here?

I knew that semcor uses wordnet senses to tag to subset of brown corpus. But I was not aware that semcor APIs can work with or without wordnet predownloaded and it will give tags in different format in these different scenarios. I honestly feel, at least semcor API documentation should have some mention of this.

So, without wordnet predownloaded, it does not return sense stems:

With wordnet pre-downloaded, it does return sense stems: