Many things are parameter dependent. May try the following:
Replace R10 by R0.001
The min DOC must be smaller than the first DOC. Therefore, replace Q10 in the second block by Q20
Replace R-375 by R-0.0375/2 i.e., R-0.01875 (R is a radius value). Use a rounded figure R-0.0188
Also, delete G90 in the first block. I believe, you are using G-code system A.
In inch mode, up to six digits after decimal are allowed for F, irrespective of the increment system being used on the machine, though it is IS-B, mostly.
Therefore, for better accuracy, may use F0.037037
For detailed information about threading (G92, G76, G32 & G34), may refer to this.