Alert ! TPM device is not detected

Hi. We use Vostro 5468 laptops at work and have been suffering for some time on some devices with the message "Alert ! TPM device is not detected" appearing on boot/POST following a BIOS update. The BIOS update is 1.20.0 and offered in Microsoft Windows update as an optional update. Laptops I've run Windows updates on and not selected the BIOS update carry on working fine. However when I have selected the optional BIOS 1.20.0 update, the install runs perfectly but when the device reboots it gets the BIOS error "Alert ! TPM device is not detected". If I click continue the laptop boots and then goes into Windows. Obviously the BIOS update has caused the problem but the laptop is now left with the annoying error message on boot and cannot carry on until the continue button is pressed.

Anyone know if this can be rectified? I have tried to manually install the BIOS update using the correct BIOS from Dell, also tried previous BIOS from Dell (still fails). If there's no solution then the motherboard is pretty much useless. See example image below - Please note this isn't the actual screenshot from my device so ignore the product name etc... ; but this is the message I get.