So you get what you pay for. The PID itself isn't bad, but the weakness lies in the relay. When the relay gets hot it tends to stick connection giving you the effect of overclocking whatever you have connected to it. Replace the relay with one with a higher temperature and you'll be fine.
Thermometer B.Well WF-4000 white
57 Review
Room temperature and humidity sensor Aqara Temperature and Humidity Sensor white
25 Review
VIVREAL 4 In 1 Stud Finder Wall Scanner With LCD Display - Center Finding Beam Finder And Sound Warning For Wood, AC Wire, And Metal Studs (Black/Silver)
24 Review
Cable tester BENETECH GM60
15 Review
Kapro 307-08-TMS Try And Mitre Layout And Marking Square With Stainless Steel Blade, 8-Inch Length
18 Review
β Stainless Steel L-Square, Size 3-Inch x 4-Inch, Zona 37-434
8 Review
Triangle Group TR918 225/45 R18 95V summer
61 Review
π CAMWAY 6 Inch Digital Caliper with LCD Display, Electronic Vernier Caliper, 150mm Stainless Steel Feeler Gauge, Plastic Digital Caliper Set for Zero Setting Inside/Outside Diameter, Depth, and Step Measurement Tool
3 Review