They're moving from cheaper (more exploited labour) in Thailand, Vietnam to more expensive (less exploited) labour in China for lower chip costs:
HP and Asus are moving some PC production from Thailand and Vietnam back to China as AI-driven component costs climb
The work is going to Chinese assemblers like Luxshare and Huaqin rather than Taiwan's server-focused ODMs, partly for access to Chinese memory
TrendForce expects the share of notebooks built outside China to slip from 24% to 21% this year, with no sign yet of cheaper PCs as a result of said move back to the country
Previously they had moved prod from China to Vietnam and Co as Chinese wages kept rising.