[Moto G5S Plus Guides, News, & Discussion] echo92:
To 'fix' that screenshot, which is normal with an unlocked bootloader, you could either re-lock your bootloader or flash a custom logo.bin. The custom logo.bin should hide the warning, but you'll still have the 5-10 second delay. For examples: https://xdaforums.com/moto-g5s-plus/themes/remove-ur-device-trusted-message-t3743443 However, flashing this custom logo.bin may affect updates.

Future updates will not likely affect this screen - as updates do not care about your bootloader unlock status, they won't lock your device bootloader. Thus, you'll keep seeing this screen on boot unless you hide it or re-lock your bootloader - it's there to alert users of your device your bootloader is unlocked.

Though re-locking the bootloader is outside the scope of this thread, here's one method that works for the G4 Plus and may work for the G5S Plus. I have not tried this on the G5S Plus however. Again, be warned that your device will be erased, that you will not get your warranty back and you'll need your OEM unlock code to unlock your bootloader again. Also, if you experience any stability issues whilst locked, you'll have to try to unlock your bootloader or pay for a repair - there's not much we can do with a locked bootloader.

1)Enable OEM unlocking. Go to Settings>About Phone. Tap the build number 7 times. You should see a toast popup about Developer Options. Head back to Settings>Developer Options. Toggle OEM unlocking on - if this is greyed out, you may have to root.

2)Ensure you have the latest fastboot firmware available. You can only re-lock with firmware as new or newer than your device's bootloader version. For you, check you've got NPSS26.116-61-11 in your ADB folder.

3)Boot your device to the bootloader and attach to your computer.

4)Use the OEM lock commands along with a full flash to try to lock your device. Verify the number of sparse chunks are correct BEFORE you flash:

fastboot oem fb_mode_set
fastboot oem lock begin
fastboot oem lock begin
fastboot flash partition gpt.bin
fastboot flash bootloader bootloader.img
fastboot flash modem NON-HLOS.bin
fastboot flash fsg fsg.mbn
fastboot flash dsp adspso.bin
fastboot flash logo logo.bin
fastboot flash boot boot.img
fastboot flash recovery recovery.img
fastboot flash system system.img_sparsechunk.0
fastboot flash system system.img_sparsechunk.1
fastboot flash system system.img_sparsechunk.2
fastboot flash system system.img_sparsechunk.3
fastboot flash system system.img_sparsechunk.4
fastboot flash system system.img_sparsechunk.5
fastboot flash oem oem.img
fastboot erase cache
fastboot erase userdata
fastboot erase DDR
fastboot oem lock
fastboot oem fb_mode_clear
fastboot reboot

The first 2 OEM lock begin commands are not a typo - the first command will ask you to repeat the command to confirm you want to re-lock your bootloader. You will need to clean flash your device again - locked bootloaders are very strict about having the correct and same firmware on your device. Failure to flash the same and correct firmware (matching the bootloader) will cause your device to fail to boot. If your firmware is not new enough, you'll see 'security downgrade' and 'preflash validation errors' as your firmware does not match that expected by your bootloader.

If you have issues with locking, you may wish to open a new thread in the Question and Answer forum as locking the bootloader is outside the scope of this thread (and to keep it clean for pizzaboy192)