I am a novice in this department, so all help will be gratefully appriciated.

I have recently purchased a secondhand Metz 45 CL 4. Following the instruction booklet seems quite straightforward, but I have the following problem/query.

I use a Sekonic Dualmaster L-558 that has the ability to wirelessly take flash exposure readings.

The metz GN for ISO 100=45

If I set the Metz to manual mode and use GN/distance I get a reading on my meter that makes perfect sense. So for example at 4 metres I get around F11 on the meter at ISO/100

However, if I then change my Metz to automatic mode and set it at F11, the reading I get on my meter is around F5.6.

Am I missing the point or should my Metz be delivering a reading to my meter of F11 in Auto mode when it is set to F11 itself and at 4m range.

I would also add that when set to Auto mode the auto check indicator seems to illuminate correctly (F16 on Auto will not illuminate the auto check at 4m, but F11 will)

Thanks in advance