I have categories set up.
A recent update added suggested conversations within already created categories.
You aren't addressing the issue.
1. What Note model do you have specifically?
2. What app is this? The OneUI stock Samsung Messages app? Try submitting an error report through the Samsung Members app if you're suspecting a software issue.
2. What software build are you on specifically? (Settings > About Phone > Software Information > Build Number [last 4 characters])