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I have a Samsung Galaxy A50 and in the last day or two I have stopped receiving delivery notifications when I send text messages
There was a recent thread about the same issue @katie48
The people had this turned On in their phones but they were not receiving delivery reports.
There wasn't a solution.
Current Phone > Samsung Note 10+ 5G _256Gb > Model: SM-N976B.
Samsung One Ui 2.1 / Android 10.
Samsung Gear s3 Frontier Watch.
Samsung Galaxy Buds.