After replacing the battery (using OBD port memory saver) for first time since purchasing the Honda Jazz 2017 I-VTEC 1.3 NAVI (known as Fit in US) we noticed that the keyless entry system just stopped working.
We could lock/unlock the car using physical key in the keyfob, and also start the push-button ignition by presenting/touching the key to the button, with radio and nav all working normally.

Upon inspection of the engine compartment fuse box and reading off the owner's manual, we noticed that the UB ECU fuse (manual diagram ref #20) was missing!! Pls see attached photo of the fuse box. Also, the sub fan fuse identified as #23 (30A cartridge type) was missing too, which is also contrary to the owner's manual. However, the 30A DC/DC fuses (#11 and #24 were fitted).

Fitting a 7.5A missing fuse for UB ECU (#20) resolved the issue with the keyless entry and car starting/ignition system.
My question therefore is, are the two DC/DC 30A cartridge (#11 and #24) shown in photo below needed? There isn't sufficient information in the owner's manual about them. And I have seen fusebox images online of similar Fit models that only show the Main fan and Sub Fan fuses.

Any pointers in this respect would be appreciated. Thank you.