Squats and Hip Flexors

i have restarted squatting after a layoff of at least a year. The last 12 months has had a very strong focus on kettlebells and perfecting my technique and completing ROP and moving into other territory that i hadn’t experienced previously conditioning wise.

Now i have begun a program to incorporate barbells and kettlebells and for 3 weeks, with the weights fairly light all was well. however as the weights are now moderately heavy i have started getting some soreness in my left hip flexors. I have iced it and rested it and it seemed to go away but then i tryed to squat again and it returned.

So you have all the information i squat LOW, almost bum to floor, so i’m guessing it may be a flexibility issue, it is not really sore just uncomfortable.

Do i stretch it out as in super joints/ relax into stretching or is there something else i should try.

Cheers in advance for any help provided!