I would normally expect water peak in DMSO to be around 3.3 pm. I've never seen water in DMSO at 4 ppm but as Corribus suggested, addition of D2O helped. The peak shape was improved and it moved to 3.6 ppm. Take a look. Thank you for advice.
PS. What threw me off a bit was that the compound is a phenol and in the previous spectrum, the -OH was present at 10 ppm. If it exchanged then it should be just the broad peak seen at 4 ppm, no?