Text messages saying delivered but never received

I have a samsung galaxy note 8 and sporadically over the last few months friends have told me they didnt receive my texts. It comes up on my end as delivered so I'm not sure why this is happening. To clarify these are a mix of picture and regular texts sent to people on all different networks. Any ideas? Someone told me maybe it was because I had power save mode on but I didn't think that would make much of a difference. Thanks!