Unlikely the tire change has anything to do with your brake issue.
There could be several thing going on:
1. Cracked pad. 2. Caliper hanging up (not completely releasing) 3. Bent guide pin allowing the caliper to become unsquare with the rotor. 4. Sticky guide pins keeping the caliper from sliding freely 5. Some debris caught between the caliper and the rotor.
You need to disassemble that side and investigate further.