Without more information about the precise setup it's hard to say whether you're doing something wrong, but my guess would be it's probably mostly just a mismatch between your expectations and the capacity of the system you've got.
460 (ah) * 0.50 (usable capacity) * 12 (volts) = 2760 watt hours
90 (watt starlink usage) / 0.8 (inverter efficiency guess) = 112.5 watt usage
2760 (watt hours) / 112.5 (watts Starlink usage) = ~24.5 hours
That's assuming the batteries are new, getting fully charged every day, and you want to discharge them to 50%. In reality you probably don't want to discharge your batteries that far and there probably will be days where they get less than fully charged.
Once you add in the freezer - if it really uses 150 watts on average - it is easy to explain why you'd be running out of power...
150 (watt freezer usage) / 0.8 (inverter efficiency guess) = 187.5 watt usage
2760 (watt hours) / [112.5 (watts Starlink usage) + 187.5 (watt freezer usage)] = ~9.2 hours
Voltage isn't a good predictor of lead acid battery capacity so you can't expect a low voltage cut-out to reliably halt usage at a given percentage of charge. Also, these are best case scenarios. Any wear on the batteries or imperfect care (watering, sub-optimal charge profile, etc) will make things dramatically worse.
Starlink power consumption:
https://www.jeffgeerling.com/blog/2021/using-shelly-plug-monitor-starlinks-power-consumption
Best lead acid battery reference (IMHO):
https://www.sevarg.net/2018/04/08/off-grid-rv-lead-acid-maintenance-charging-failure-modes/