LO: set dimensions to inches, .001 precision

I am trying to dimension my model in LO but cant get the dimensions to come out right.

for instance 6.755" on the model comes out to 6.80" in Layout?
I need to define a lot of dimensions to.001" precision.
I am beginning to wonder if I wasted my money for a pro licence that cannot do what I need.
I know I can overwrite the dimension text but that kind o defeats the purpose doesn’t it?

thank you in advance for your kind and honest reply’s.

Select the Dimension tool and refine the Precision. Select existing dimensions and change their precision, too.
Screenshot - 3_15_2020 , 10_19_54 AM

Thanks but.
Why is that not available for me?

Are you still using LO 2017?

Thanks! yes I am.

Might want to check out LO2020.

OK thanks!