Shopping Cart Time not being stored

Did you check your order refresh settings? See the attached screenshot.
If it's configured to "Refresh a draft order when it is loaded regardless of who it belongs to." that might explain it.
When the cart is about to be expired, the loadUnchanged() method is called when loading orders precisely to avoid refreshing the order and thus updating the changed time.

@jsacksick yes it is set as shown in your screenshot.

Upon further testing, the "Updated" time resets for all existing orders pending in the shopping cart when a new order is added to cart.
But this "reset" only appeared 1 time.
No errors or warning appears in the dblog.

Maybe some kind of cache issue?

No errors appearing on dblog for this issue.
But I did notice a behavior. The Cart "updated" time does not reset for logged in users.

Only resest for "Guest" / anonymous users that has added to cart.

Automatically closed - issue fixed for 2 weeks with no activity.

Issue resolved with Commerce core 8.x-2.37 update.

Still not sure of the cause.

I think this was fixed by the patch from 🐛 Skip Order Refresh on draft anonymous orders on CLI Fixed .