Hi and welcome from North Carolina.... I have a generic walking foot and have no problems. I tend to keep it on my machine all the time because it is so hard to get it on. I'd check to see if it's on correctly before changing the tension.

If puckering is your problem, you may have too much tension on the presser foot. On vintage machines and sometimes on newer machines, you can "turn down" the pressure on the presser foot. On vintage machines, the knob is generally on the top of the machine straight above the foot. You just twist it - "righty tighty, lefty loosey".

(I have no clue how to handle it on electronic machines.)

Try that on your practice piece and see if it helps.

bkay

Thank you so much ladies for all your advice. After buying a new machine needle and checking everything, I found my problem was a too loose bobbin tension. After sorting this out my walking foot and machine are both behaving themselves.

Welcome craftynanny from another Australian in Victoria! Glad you sorted your problem out. Would love to see a pic of your placemats?