LS,
I’ve found a solution. Apparently some players had a similar issue on DCS MT and their workaround fixes the TCS and LANTIRN image problem on the VDI. I have this issue on the standard DCS but the same solution works too:
Starting the mission from the mission editor gives a normal functionality for the imagery of the LANTIRN in the front cockpit.
To get the bombs drop I jumped in to the rear cockpit and although on the armament panel all the switches were set correctly, I switched them all off and back on again as a reset and this worked.
The strange thing is I only have had this issue in mission 12 of S&A. For all other missions the F14 works as advertised.
In any case, problem solved.
Thanks for your input,
N.
NicolasDf's post in Speed and angels mission 12 LGB part was marked as the answer