That is completely normal.
In other Images it shows signal even if there is no lock
OpenPLI only shows signal, if there is 100% stable signal! This makes it hard to check something on low signal transponders.
Where do you draw that conclusion from?
OpenPLi's enigma just continuously displays the information it gets from the tuner. If the tuner doesn't give SNR/AGC/BER information when there is no LOCK, there is really nothing to display. And so, yes, it depends on the hardware and the drivers what is displayed. I've experienced that aligning a tuner with a VU+ receiver works very well, info is updated multiple times per second. On some other receivers the information is updated very less frequently, sometimes only once per 3-5 seconds. Some receivers also stop trying to tune again when the signal has been gone for a short while, for instance when you obscured the LNB during aligning. You then need to select another transponder and switch back again to force it to tune again.
Update interval is 100 ms. If you experience something different something wrong.
self["Frontend"] = FrontendStatus(frontend_source = lambda : self.frontend, update_interval = 100)