If for a 40 m dipole the antenna wire is about 0.4 mm dia (copper) and the coax is RG174 or similar thin 50 ohm coax then the resistance from centre to outer of the coax with the antenna ends connected will be about 5 ohms on my calculations. I prefer to use a little heavier gauge wire so my dc resistance check values are lower.
So if seems your antenna is OK in regard to continuity. I initially thought it too high but for light gauge wire it is normal. Good to have some reference values.
So can you confirm your apex was at 6 m. Impedance varies with height.
Can you confirm the ends were supported by the supplied ropes and the end pegs were on about the same horizontal plane. The included angle between the wires is more important than whether they are in a straight line.
The feedline of course should come down the mast and therefore be symmetrical with the radiator… It doesn’t have to be perfect but if it were to be run close to one radiator the results would show up on the SWR…
Do you have an impedance analyser? If so you can measure the antenna parameters outside as well as inside the band to see where the apparent resonance is - no reactive component - and where the minimum SWR is. You are at the end of I guess 7 m length of coax so the values you measure will be a bit different at the feedpoint but at the end of the day you want a low VSWR at the coax connector.
Your SWR meter might not be accurate. Check it with a 47 ohm and a 220 ohm resistor.
My experience with this manufacturer has been SWR less than 2:1 on an 80/40/30/20 link dipole. 5:1 isn’t acceptable but if all the above checks our OK I’m out of ideas.
Of course Compton has a point, backing the car off can only help.