I love Jian Yi and XiXi's relationship, which is why it annoys me when people get demanding with their desires to see the two have a more physical relationship like Old Xian depicts with He Tian and Mo. Not all couples, even romantic ones, express their love and desire in overly physically affectionate ways. That doesn't make their love and feelings less valid. Maybe Old Xian is portraying JY and XX as that kind of relationship. Or, maybe not. Only he knows, but regardless of why he doesn't have them hot & heavy, I think he has shown the depth of their feelings and commitment to each other in valid ways already.
Old Xian has updated with some new content recently on his Weibo and X (Twitter) pages. On Twitter his official page can be found at @old_xian. He did take a long break but he posted Valentines and Chinese New Year content for both couples. You will have to run them through a translation program though.
Has it been confirmed that Old Xian is a man? I thought that their pronouns were unknown