Bhagat Bheekhan Ji has two hymns in the Guru Granth Sahib Ji, in Sorath. He is generally identified with Sheikh Bhikhan of Kakori near Lucknow, a Sufi who died in 1573, in Akbar's reign.
If that identification holds, he was a near contemporary of Guru Amar Das Ji, and his compositions entered the collection within a generation of his death rather than across centuries.
The two hymns are about the body's ailments and the one medicine. They are short and clinical.
He is one of two Muslim Sufis in the volume, the other being Sheikh Farid Ji, which is a small number that is nonetheless larger than the number of Sufis in any other scripture of the region.
The two Sorath hymns use the language of illness directly. The body is described as failing, the eyes going, the ears going, the strength going, and the one remedy named is the Name. The imagery is medical rather than metaphysical, which is unusual in the volume.
The identification with Sheikh Bheekhan of Kakori in Awadh rests on tradition rather than on anything internal to the hymns. If it holds, he died around 1573. If it does not, nothing at all is known of when he lived.
Kakori is a town near Lucknow now and has no shrine identified with him that draws Sikh visitors. The relationship between the volume and the Sufi establishments of Awadh is one of the least examined parts of its formation.