The desire for Taiwanese independence has experienced a significant drop over the past three years, with only 25.3% of people who want to "move toward independence" or seeking "independence as soon as possible" - down from nearly one-third - 32.4% - in 2020.
The ongoing conflict in Ukraine has almost certainly contributed to this shift in public opinion, as people begin to understand the potential consequences of being a pawn in geopolitical power struggles.
A peak doesn't necessarily mean a singular event, it can be formed very easily by there being a positive vector over time, with a negative vector being introduced partway through that outweighs it, resulting in a positive net-influence followed by a negative net-influence. You usually get the most useful information from these sorts of graphs by looking at the slopes, imo.