Let's check why the transfer entry isn't showing up on the Checking account when reconciling the bank, relaxchalet.
I've replicated this on my end here are the screenshots you can view for your visual guide. They're both showing as cleared on the bank register.
You need to make sure that the custom date selected on the Reconciliation page includes the date when you create the transfer in QuickBooks. See the image I've attached below.
If the same issue persists, you can change their status from cleared (C) to blank. Then, check them again when you reconcile the account.
You can also perform a troubleshooting step, like clear the browser's history. Too much file in the cache can impact the data being transmitted in QuickBooks. As an alternative, you can use other supported browsers to have the most secure experience.
If you're still unable to see those transfers in both accounts, the entry is maybe damage. You can delete and re-create it.
Let me know how everything turns out by commenting below. I'll be around until you're able to see the transfer on both the Checking and Savings accounts.