QGIS TIN interpolation - error in pixel size of output

When using the “TIN Interpolation” tool in QGIS 3.10, the output raster file doesn’t keep the pixel size I specify. For example if I specify a pixel size of 1.0m, the output file actually has a pixel size around 0.99m. The pixels also aren’t perfectly square sometimes. Has anyone else experienced this problem or discovered a solution?

I have pasted below example screenshots of two parameter values, and the properties of the output files I get.

Overall for this example I want to get an output raster with 500 rows and 100 columns, pixel size 1.0m. It’s impossible to enter this in the parameters because when I change one value, another changes. e.g. when I enter a pixel size of 1.0m, the ‘Rows’ parameter updates to 500 and the ‘Columns’ parameter updates to 101. If I change the ‘Columns’ parameter to 100, the ‘Rows’ parameter automatically changes to 495 and the pixel size changes to 1.0101.