Never confuse someone being comfortable with you for them valuing you.

Being at ease around you is not the same as valuing you. Comfort can mean someone appreciates you or simply that you are convenient, undemanding, and require nothing in return. The difference shows up when something is asked of them: effort, inconvenience, or a moment of standing up for you. Ease is pleasant and it is not evidence.

Look at whether the comfort runs alongside effort. Do they remember what matters to you, or show up when it is difficult. If the relationship is only easy for one of you, that is worth noticing without turning it into a confrontation.