OK, the question in the back of my mind is still the validity/integrity of the installers you are downloading, if you are not able to download "as is" from Apple.
In any case, here's something else to try... This is the point of hackintoshing, if 1 thing doesn't work, try another; if you keep trying long enough, solve enough problems, you'll get it working!
it's all part of the adventure!
Personally, I always create my flashdrives manually. You can try this if you like:
1. Open terminal, then use DiskUtil list to find your flashdrive's number.
2. From terminal, run:
diskutil partitionDisk /dev/diskX MBR FAT32 CLOVER 500m JHFS+ INST-MOJAVE 0b
(replace X with the disk number of your flashdrive).
Explanation: This line is using diskutil to create 2 partitions on disk X, 1 fat32 partition size 500mb (will work as your EFI partition, and will hold Clover). The next partition is an HFS+ partition that will take up the rest of the disk (0b), and will be used for the Mojave installer. Note that the disk is using MBR, not GPT, but this still works fine, as there will be a fat32 partition with the EFI folder/structure in it, so the board will boot fine
Tip: if you'd like to have more than 1 installer on a single drive, all you need to do is partition the flashdrive into more partitions. I have a 32GB drive with Mojave, Catalina, and a "tools" partition where I place all my hacking stuff
3. Once the drive is partitioned, run:
sudo "/Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia" --volume /Volumes/INST-MOJAVE --nointeraction
Explanation: This is simply running the createinstallmedia app to create the installer on the previously create INST-MOJAVE volume. Note that this requires the Mojave installer to be in the applications folder and to be named correctly (e.g. that the name hasn't been altered).
This should create the Mojave installer and rename the volume...
4. At this point, you can either copy an existing EFI folder with the proper Clover structure in it (E.G. EFI/Boot, EFI/Clover etc). Otherwise, you can use the latest Clover installer and install Clover on the "CLOVER" volume that was created earlier. If you use the installer, be sure to change the install location to the "CLOVER" volume, and then select customize. In customize, select install Clover for UEFI booting only (or similar language), and uncheck the install Clover in the ESP (or similar language). Then make the rest of your selection, and install...
Once you install, you have to add the proper kexts to /EFI/Clover/Kexts/Other and any required EFI drivers to /EFI/Clover/Drivers/UEFI (for newer clover revisions) or /EFI/Clover/Driver64UEFI (for older Clover revisions).
Finally, if the createinstallmedia app fails or cannot create the proper installer, then your installer is probably corrupt. At this point, you may want to do as TRS96 suggested and try downloading 10.13.6 (High Sierra) if your MacBook supports it/allows it.