Row and Cell formatting issue via the API picking up previous row strike through



I'm creating rows in Smartsheet via the API

We're are storing the Sheet and Row ID in the originating application.

Later on someone might decide that they no longer want this record, but rather than delete it from Smartsheet we update the formatting of that row. Reading the row in, updating each cells formatting so bit 5 of the formatting is on. Update the row and each cell contents is struck-through as expected.

All good so far.

Now if each cell of the the current row is formatted with strikethroughs and I add a new row, the new rows sometimes gets strikethroughs as well. Issue is it's inconstant. Sometimes all the cells of the new rows are struck-though, other times it's odd cells 1 to n.

I have even sent the formatting for each cell with bit 5 set to zero on the new row insertion.

Somehow Smartsheet is picking up the previous rows formatting. If I manually enter a new row it does not do this.