SAM D21 on MKR Zero doesn't work with DS3231 RTC

Have been trying to integrate DS3231 RTC to work with MKR Zero through the I2C bus without success. Other units on the bus like a BME280 work, and when scanned, the board returns the address of the RTC and its on board memory chip. Used several DS3231 libraries including RTClib but none seem to work. After changing the date and time in the code using the example code from the library, the unit always returns the same date 2 Feb 2019 (yes, USA groundhog day!). The clock module works great with an Uno. Suspect it could be a timing issue, but can't see any obvious suspects in the library source code.

Start with the RTClib example and the library source mentioned in the report, then compare DS3231 behavior on the MKR Zero with the working Uno setup. Check the SAMD21 I2C interaction and determine why the RTC always returns 2 Feb 2019; done means the date and time can be set and read correctly on the MKR Zero.

Written by the indexing model from the issue text.