Discussed in this thread
https://aseannow.com/topic/1169664-thai-immigration-announce-changes-to-tm30-reporting/
In the OP take note of Para 2.2....
2.2 After the house holder, owner or possessor of the premise of hotel
manager has reported as defined in Article 2.1, the same alien has left the premise and
returned for another stay within the valid period, the house holder, owner or possessor
of the premise of hotel manager do not need to make another report;
The alien as defined in paragraph one shall include those who
being granted multiple-visa who leaves and returns to the Kingdom with specified
time in the visa, and those with re-entry permit.
Previously, most immigration offices in Thailand wanted a new TM30 report within 24 hours every time a person left and reentered the country. This change eliminates that requirement.