Check inside the engine bay fuse box, remove the multi plugs and check for corrosion. Done a few now where the pins on the fuse box module have broken due to corrosion (always seems to be one of the large multi pin plugs) I'm sure Peugeot must squirt a bit of salt water in there from the factory as there's a cover on the box and it can look like new in there lol. If it is that, you will need a new module (circa £180 from Peugeot). Last one I did had been to a 'garage' and they gave up because there was "so much wrong". Often the simple things if there's multiple electrical issues at once.