Something off in SQL expression for criteria

Summary

Trying to capture last month's data

Content

The report functions with the expressions below; however, It doesn't seem to actually capture the last day of the previous month. I run the data for May and know there are results for 5/31 but only captures up to 5/29. What is wrong with the expressions. The Beginning of Previous Month expression seems to capture from 5/2 and I have verified that is correct.

Beginning of Previous Month

TIMESTAMPADD(SQL_TSI_MONTH, -1, TIMESTAMPADD(SQL_TSI_DAY, DAYOFMONTH(CURRENT_DATE) * -(1) + 1, CURRENT_DATE))

End of Previous Month

TIMESTAMPADD(SQL_TSI_DAY , -(1), TIMESTAMPADD( SQL_TSI_DAY , DAYOFMONTH(CURRENT_DATE) * -(1) + 1, CURRENT_DATE))