Sometimes Permalink structure on WordPress is corrupted.
You can recover from that situation with disabling Redis Object Cache and updating Permalink structure.
Step 1. Select [Settings] Menu on left sidebar, then click [Redis] menu.
Step 2. Click [Disable Object Cache]
Step 3. Redis Object Cache has been disabled
Step 4. Click [Permalinks] menu then [Save Changes] button without changes anything to force update Permalink structure
That's all.
Let's check Permalinks are updated.
Make sure enable Redis Object Cache plugin again before terminating WordPress.