The message is saying that when resolving Lava using Fluid, it is not resolving same as Liquid. If you look closely, the difference is the "at" between date and time:
That is likely due to how Lava is trying to format date by escaping the "t" character with "\" symbol:
I would suggest breaking that date format into two separate outputs, one for the date, and one for the time. Like this:
... on {{ locModifiedDate | Date:'MMMM d, yyyy }} at {{ locModifiedDate | Date:'h:mm:ss tt' }} ...