Digital home scales are pretty accurate.
The only accurate weight would be nude so maybe you were wearing more clothes at home?
At any rate, big swings like this can always be attributed to water weight. And a diet high in salt will make you retain water. So start tracking your salt as a custom nutrient would be a suggestion. Plus the water weight can be from TOTM as I'm sure you're aware.
Think of food as fuel for the body instead of feeding emotions