Can you please paste your output from running below?
$ gcab -x 4e3f12fc1901c05790ab17ff2223a79631477aa87979498874c4c262cfafc144-WD19FirmwareUpdateLinux_01.00.21.cab
$ jcat-tool verify ./firmware.jcat --public-keys /etc/pki/fwupd

package.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
ec.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
vmm5331.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
rts5413.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
rts5487.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
titanridge.bin:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
package.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
ec.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
vmm5331.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
rts5413.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
rts5487.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
titanridge.metainfo.xml:
    FAILED sha1: verifying data is not supported
    FAILED sha256: verifying data is not supported
    PASSED pkcs7: O=Linux Vendor Firmware Project,CN=LVFS CA
    PASSED gpg: 3FC6B804410ED0840D8F2F9748A6D80E4538BAC2
    FAILED: Validation failed
Validation failed