"My daughter-in-law and I have known each other for more than four years, and it has been going well. I studied as a graduate student from the initial university until she was admitted to the civil service. My parents know about our relationship, and her mother agrees with us. You did a lot of needlework for me, too. Thank you for your excitement. This shows that your relationship has been relatively strong, which can be described as "suitable for each other", just waiting for the sedan chair to come and marry the bride. This is already a nail in the coffin.
My mother-in-law "ignored" you, not because he deliberately alienated you, but because of his personality. There are such people in the world, and old people have seen them. I hope you don't care about his behavior, just pretend that there is no him, and just say hello when necessary! He will not pose any threat to your relationship with your daughter-in-law
If you don't trust old people, you can ask your daughter-in-law. Of course, she will tell you her father's temper and you will know what to do next.