Custom CSS doesn’t work with multiple tables on same page

I am having an issue with two tables on the same page using Custom CSS, where the 2nd table does not make use of the CSS defined for it. The same table CSS however, on another page where that table is by itself, is working with the defined CSS.

The Custom CSS is shown below, where table id 7 is the first table that works, and id=8 is the second table on the first page that doesn’t work, and the only table on the second page where it does work.

.tablepress-id-7 .row-1,
.tablepress-id-7 .row-16,
// … removed to reduce size here
.tablepress-id-7 .row-106,
.tablepress-id-7 .row-108 {
background-color: #d9edf7;
font-weight: 700;
}

.tablepress-id-8 .row-1,
.tablepress-id-8 .row-5,
.tablepress-id-8 .row-12 {
background-color: #d9edf7;
font-weight: 700;
}

I have six other tables in the Custom CSS defined similarly, but I only use one table on a page in all other uses. And in all other uses, with one table per page, they work fine.