IOS 18 Update Makes it Difficult to Text

I just updated my phone to IOS 18 and everything has been fine, but my mom has an Android phone and my phone doesn't let me text her cell phone number. She has an iPhone 15 as her work phone and whenever I text her cell phone number it automatically corrects to her work phone number even though I have deleted and blocked her work number multiple times. Whenever I text her cell phone number the messages send green because it is an Android, but then she will text me back saying I am texting her work phone. This problem is recent because the first couple of days after I updated my phone to IOS 18 it was working fine, I don't know what happened.