Output is NaN for a specific date format

**Describe the bug**
When I try to use dayjs with customParseFormat to parse a string like "20 Nov, 2022" to a date object, It is not able to parse it. I get NaN in return.

Code
` dayjs('20 Nov, 2022', DD MMM, YYYY').toDate()`

If i remove the comma, present after the Month name, It works fine.

**Expected behavior**
It should return a date object.

I am using it in a React Native Project.

**Information**
- Day.js Version = v1.11.0
- OS: = iOS
- Browser [e.g. chrome 62]
- Time zone: [e.g. GMT+05:30 IST (Indian Standard Time)]

Start at the customParseFormat plugin entry point and reproduce parsing of "20 Nov, 2022" alongside the comma-free form. Done means the comma-containing input returns a valid date object without regressing the existing format behavior; the issue names no source file or test.

Written by the indexing model from the issue text.