Bug: Inverters permanently "lost" when probe() runs at night

[smcneece]

The Problem:

If pypvs initializes (or reinitializes) at night when inverters are offline, it never discovers them - and never recovers until a full HA restart during daytime.

We've had multiple users report this in the Enhanced SunPower integration, as well as I know users of the SunStrong integration have seen the issue.

• Restart HA at night → inverters show 0 power forever (until next restart)
• Restart HA during the day → everything works fine
• Some users see it after 3-4 days (likely session timeout triggering reinit)

Root Cause

I traced through the pypvs code and think I found the issue in pvs.py:

The probe() method only runs once - when self._supported_features is empty:

async def update(self) -> PVSData:
    if not self._supported_features:  # Only runs once!
        await self.probe()

    for updater in self._updaters:
        await updater.update(data)

And in production_inverters.py, the probe catches exceptions and returns None:

async def probe(self, discovered_features) -> SupportedFeatures | None:
    try:
        await self._request_vars(VARS_MATCH_INVERTERS)
    except ENDPOINT_PROBE_EXCEPTIONS as e:
        _LOGGER.debug("No inverters found...")
        return None  # Not added to updaters list

So here's what happens:

1. HA restarts at night (or session times out, or whatever triggers pypvs to reinit)
2. update() is called, sees empty _supported_features, runs probe()
3. Inverters are offline - PVS returns no data or an error
4. PVSProductionInvertersUpdater.probe() catches the exception, returns None
5. Inverters updater is not added to self._updaters
6. self._supported_features is now set, so probe() will never run again
7. All future update() calls skip the inverters entirely
8. Only fix: restart HA during daytime so probe() runs when inverters are online

Suggested Fixes

A few options:

1. Re-probe when inverter count is 0 during daytime - If we know it's daytime (sun is up) and we're seeing 0 inverters, something's wrong. Re-run probe.

2. Always include inverters updater - Let update() handle empty/missing data gracefully instead of excluding the updater entirely from the list.

3. Don't make permanent decisions at night - If probe fails to find inverters, maybe flag it as "needs re-probe" rather than "inverters don't exist."

4. Periodic re-probe - Re-run probe every X hours to catch any devices that were offline during initial discovery.

References

• Enhanced SunPower Discussion #48: Missing Energy production on all inverters but Powermeter shows production smcneece/ha-esunpower#48
• Enhanced SunPower Discussion #49: Need to reboot HA every few days to get PSV5 data collection smcneece/ha-esunpower#49
• Enhanced SunPower Issue Document GET requests also supported #39: [Bug]: No errors, but all power returns 0 while production in full swing smcneece/ha-esunpower#39

Happy to help test any fixes. Thanks for maintaining pypvs!