PEX Pipe Snakes in Basement

We have an oil furnace and boiler with baseboard. We had an addition and new zone added on to our house. The new zone uses PEX pipe. The new PEX loop runs from one end of the basement to the other end.

When the PEX heats up it "snakes" in all the sections between where it is fastened to the joists.

Should it snake so much?

With it snaking like that, what's the best wat to insulate it?

thanks
Wes