This is not a bug. It depends on how many games you played.
bug?? - Draw Stats

Previously reported issue. See Bug [ ]: Stats Occurrence table's Draw stats incomplete and Bug [ ]: Stats occurrence table missing entries
Both reported July, 20, 2021 when the new stats layout was first released. Not sure why they haven't been addressed.

I think the percentages are rounded up, so it wouldn't match. For example, 5.5+4.5=10, but when you round it up, you get 6+5=10

why the percentage doesn't merge into 100%
Those aren't the only ways to draw games
You might have drawn game due to Insufficient material , Timeout vs Insufficient material and 50 Move rule

As stated in #7, it is a known issue
In my case for Rapid Draws it reports this:
and is missing parts,
Result | Count | Draw % | Game % |
Agreement | 4 | 8.89% | 0.38% |
Repetition | 23 | 51.11% | 2.16% |
Stalemate | 1 | 2.22% | 0.09% |
Insufficient Material | 8 | 17.78% | 0.75% |
Timeout vs Insufficient material | 9 | 20.00% | 0.85% |
50 Move Rule | 0 | 0.00% | 0.00% |
Total | 45 | 1063 |
The missing entries

why the percentage doesn't merge into 100%
Those aren't the only ways to draw games
You might have drawn game due to Insufficient material , Timeout vs Insufficient material and 50 Move rule
that must be true

how about to suggest to add the disregarded sections?
Done back on July 20 via Report a Bug screen shots of topics Bug [ ]: Stats Occurrence table's Draw stats incomplete and Bug [ ]: Stats occurrence table missing entries, with link references to the topic in the message body.

I was told only the top 3 show and that the other types probably won't be added until a future redesign.

I was told only the top 3 show and that the other types probably won't be added until a future redesign.
thank you for answering

I was told only the top 3 show and that the other types probably won't be added until a future redesign.
It clearly isn't the top 3, better said it is just 3. For example 2.22% isn't greater than 17.78% or 20.00% as reported in Bug [ ]: Stats Occurrence table's Draw stats incomplete.
In my case for Rapid Draws it reports this:
and is missing parts,
Result | Count | Draw % | Game % |
Agreement | 4 | 8.89% | 0.38% |
Repetition | 23 | 51.11% | 2.16% |
Stalemate | 1 | 2.22% | 0.09% |
Insufficient Material | 8 | 17.78% | 0.75% |
Timeout vs Insufficient material | 9 | 20.00% | 0.85% |
50 Move Rule | 0 | 0.00% | 0.00% |
Total | 45 | 1063 |
As to requiring a future redesign, that is disappointing answer. The bug fixes only requires including the 5 missing entries:
No design required. The shortcomings are known, the fix is simple. Chess.com's setting the priorities for reported bugs detected at initial Beta release are just misguided.
why the percentage doesn't merge into 100%