TORONTO—Canadians are expressing frustration at still being unable to drive across the border to the U.S. for a casual visit, even though their fully vaccinated American counterparts will soon be able to do so. The federal government recently said restrictions on U.S. citizens and permanent residents fully immunized against COVID-19 will ease Aug. 9. Canadians, however, are seeing no similar relaxing of rules. On Wednesday, the U.S. Department of Homeland Security extended its COVID-19 restrictions on travel by land from Canada until at least Aug 21. Air travel to the U.S. is permitted with certain conditions. For baseball fan Jeff Chatterton, the situation means he isn’t able to drive across the border to take in a Toronto Blue Jays game like he used to do before the pandemic hit. “I’ve done everything (that was) asked—I’ve worn a mask, I’ve gotten the vaccines, I’ve stayed home. Science says I’m safe, when …