I bought a Sonoff SNZB-06P sensor and eWeLink recognizes it by name, but it doesn’t give me any possibility to set the sensitivity or timing, it sees it as if it were a simple PIR sensor. The firmware version is not displayed in the details.
Does anyone have any idea what is going on?
…and your sensor is connected to… ?
…to Sonoff Zigbee bridge(not Pro)
Sonoff ZBBridge Pro or NSPanel Pro or iHost is needed for it to function properly. ZBBridge (not Pro) is based on a chip that is unable to support newer devices, to put it simply. This is promptly stated on the SNZB-06P product page.
Thanks, Jam3, but I have seen in several places that it also works with other ZB hubs… my mistake. 
Some others also have limitations, the same as ZBBridge. Depends on the chip that sits inside.
I once came across a description of flashing ZBBridge with alternative firmware. The author claimed that this expands the capabilities of the device. If you think it’s worth going down this route and you have the knowledge, do a research. It might just work. On the other hand, it is better to invest in newer generation hardware. The Pro version is not murderously expensive, and sooner or later you’ll hit another incompatibility problem. Every bridge has a connection limit, so a non-Pro version will come in handy. Or use it for dumber devices, like buttons or remotes. You may as well convert it to be a router/repeater.