Unable to receive any calls in Mainland China

I went to Mainland China back in January and was unable to receive any incoming calls from the United States or anywhere else. Outbound calls worked perfectly. This wasn't an issue in 2019 and 2020 but it seems to be an issue now. I have an iPhone 13 Pro using eSim.

Does anyone have any solutions? I am going again in April and would like to resolve this before then.