aespa marked their fifth anniversary on November 17, 2025. Winter, however, did not attend the concert due to flu-like symptoms after the previous night’s show, according to SM Entertainment, which said she visited a hospital and was diagnosed with cold- and flu-like symptoms; doctors advised rest, making attendance at the soundcheck and concert unlikely.

Despite the setback, Winter was pictured with her bandmates at the milestone celebration, holding a cake and thanking fans for their support. She wore a heavy coat and a mask indoors, prompting a sense of sympathy from fans and observers.

The group is currently underway with the 2025 aespa LIVE TOUR – SYNK:aeXIS LINE. To mark the fifth anniversary, aespa released a Special Digital Single, Sync: AXIS Line, featuring solo tracks from Karina, Winter, Giselle, and Ningning.