Yes, but not recommended. Downgrading can corrupt the NVRAM (network settings). If you must, use the same QFIL process with an older, official .bin file.
are typically handled directly through the official Yifanwireless support site or by contacting their support team at . yeacomm p11 firmware download top
Let me know what you are trying to achieve or if you need help finding the right firmware for your specific network. Yeacomm YF-P11 IP66 4g LTE outdoor CPE with Lan port Yes, but not recommended