One consequence of the upcoming increase of machine-to-machine communication is saturation of the present wireless networks. The latest version of Wi-Fi, IEEE 802.11ax, has been designed to improve the efficiency and performance of wireless local area networks. To overcome the problem of dense networks with regard to IEEE 802.11ax, orthogonal frequency-division multiple access (OFDMA) was introduced. The protocol was designed with a flexible standard around the radio allocation scheme for OFDMA. The flexible specification brings the opportunity to develop a radio channel scheduler. In this paper, a novel resource unit (RU) allocation scheduler is proposed for scheduling access in OFDMA. The proposed scheduler includes a closed-loop feedback controller with proportional gain to simultaneously consider priority and fairness. The combined information of quality of service and buffered data in the stations is used to allocate the data flows more efficiently in dense network conditions. Simulations show that the proposed scheduler provides efficient RU allocation in IEEE 802.11ax networks.