Source says

A GOP source says that the new $1.7 trillion infrastructure proposal laid out by Pres. Biden is not a significant improvement.

No surprise there.

The GOP want to pay for the plan via a gas tax or other use tax. The Pres. does not want to tax those making less than $400K (which gas taxes and other use taxes do), but instead pay for the plan via a rise in corporate taxes.

That is one of the first meaningful differences between the two parties (if you believe that there is "the will" to negotiate).