Applying fsolve to unknowns of type x(0)

This one works as expected:

This one fails:

That shouldn't fail.  According to ?solve,details, under the Description

heading, it says that the unknown may be a name or a function.  Note that

so there seems to be a contradiction.  Nevertheless, there is a workaround:

Now try with fsolve().  This one works as expected:

This one fails:

But the previous workaround does not help:

I can temporarily rename the variables to plain symbols, or perhaps

freeze/thaw them.  But is there a simpler workaround?