20 amp fuses in my freelander are not working

See/find what that fuse powers. If it only feeds one thing. That thing is probably bad. if it feeds multiple components, look at the ones that draw the most power, Like ignition.

It is probably the actuator. very easy to change.
https://www.youtube.com/watch?v=JpHn9gRXVXw

this is the main fuse from the battery that feeds the fuse box etc , take out the fuse and holder and check for signs of corrosion on the terminals , any worn wires etc as to blow this size fuse must be shorting to earth , when does the fuse blow ? if it is on start up then the starter could be pulling to many amps so would need replacing , if it's when driving i'd have the alternator charge rate checked as well . that gives you a few things to get on with , keep me posted if you wish

15 amp is a fair current draw and for it to blow after a few minutes means that there is a short in that circuit that is allowing a drain to earth that just exceeds the 15 amp. It is in the ignition part of the system and may be a bad connection ( water ) or a problem appearing in the ECM or relay . Run fault codes to find the area of the fault. Because it is taking time to blow the fuse, it will be difficult to find. Check all wiring for rub marks .

All of the items you listed are controlled by the Central Control Unit (AKA body control module) which is located under the right side of the dash behind the glove box.

The CCU has several battery voltage inputs which should be checked:

Fuse #8 (15 Amp), (Hot in RUN or START) and Fuse #15 (20 Amp) (HOT AT ALL TIMES) in passenger compartment fuse block.
Fuse #10 (10 Amp) (HOT AT ALL TIMES) in the engine compartment fuse block, via the inertia switch located ay the left rear side of the engine compartment.

Note: the inertia switch supplies power to pin #18 (BLUE/GREEN wire) at the CCU connector C0428. If there is battery voltage at this pin, the inertia switch is OK.

When you check your fuses, make sure they have power when they are supposed to have power. I have had many people simply LOOK at the fuses and tell me they are OK only to find out that the fuse has no power even though it is not blown. (possible connector or wiring problem to the fuse itself).

If this information is not enough to locate the problem, you will need a scan tool that is capable of two-way communication with your onboard computer network to continue diagnosis.

Check/replace relay 6,located in fuse box lower dash under steering wheel.

Your owners manual will give you a fuse diagram , with the amperage
of the fuse you need. Probably a 20-30 amp fuse.

fix the plug,car or trailer, and check the wiring and bulb sockets in the trailer
bigger fuses are equal to burnt wiring harness or fires in either vehicle

I looked in a Haynes manual and it showed a 20 amp fuse controlling the the dash/ taillights. I t sould be in the fuse block under the the driver's side dash. If you have your owners manual, there should be a fuse locator diagrahm to help you locate the right 20 amp fuse. Remember usually when your dash lights are out so are your tail lights.