Strange schedule of Voice of Nigeria on 15120 kHz 1520-1603UT June 1

NIGERIA   Strange schedule of Voice of Nigeria on 15120 kHz 1520-1603UT June 1
1520-1603 on 15120 IKO 250 kW / 007 deg to NoAf Yoruba/Igbo/Arabic, ex English
1600-1630 on  9690 IKO 250 kW / 248 deg to ECAf Swahili, not on air
1630-1700 on  9690 IKO 250 kW / 248 deg to WCAf Yoruba, not on air
1700-1730 on  9690 IKO 250 kW / 248 deg to WCAf Igbo, not on air
1730-1800 on 15120 IKO 250 kW / 007 deg to NoAf Arabic, not on air