Nothing in this part shall be construed to deprive any party, upon any judicial review of the proceedings and orders of the commission, of the right to trial by jury of any issue of fact raised thereby or therein, where such right is secured either by the Constitution of Pennsylvania or the Constitution of the United States, but in every such case such right of trial by jury shall remain inviolate. When any judicial review is sought, such right shall be deemed to be waived upon all issues, unless expressly reserved in such manner as shall be prescribed by the court.