When I use Quantity Variables the online notebook can not solve PythagoreanTheorem

f=FormulaData["PythagoreanTheorem"] /. { 
QuantityVariable["a","Length"]->QuantityVariable["l","Length"], 
QuantityVariable["b","Length"]->QuantityVariable["t","Time"] QuantityVariable["v", "Speed"],
QuantityVariable["c","Length"]->QuantityVariable["t","Time"] Quantity[1,"SpeedOfLight"]}

Solve[f, QuantityVariable["t","Time"]]

Does nothing!

But when I use usual variables the online notebook return solution

f=FormulaData["PythagoreanTheorem"] /. { 
QuantityVariable["a","Length"]->l, 
QuantityVariable["b","Length"]->t v,
QuantityVariable["c","Length"]->t Quantity[1,"SpeedOfLight"]}

Solve[f, t]

Return correct solution.

How to solve Pythagorean Formula with Quantity Variables?