I am surprised that no one pointed out that 20. Nxg6? was a serious mistake that leaves white's king vulnerable to attack. It also over complicates the position which can be seen from the analysis on the YouTube video. King safety should always take precedence over grabbing material. It seems that even GMs are not immune to these types of lapses in judgement.
Instead, white should have played 20. Qc1! threatening to exchange queens. If black then plays 20...Nc4 then 21.Qxa3 Nxa3+ 22.Kb2 and white has a modest positional advantage. if 20...Qa5? then 21.Qb2 and if 21...Nc4 then there follows 22.c3 Ba3 23.Qe2 and white is better here too.
Instead, white should have played 20. Qc1! threatening to exchange queens. If black then plays 20...Nc4 then 21.Qxa3 Nxa3+ 22.Kb2 and white has a modest positional advantage. if 20...Qa5? then 21.Qb2 and if 21...Nc4 then there follows 22.c3 Ba3 23.Qe2 and white is better here too.