Can you post your stats (age, height, weight)? We can help you better with a bit more information. So when you say are gaining, you specifically only mean in size? So you have no actual weight gains on the scale? You do need to increase up to at least the next activity level and eat more calories. You workouts alone add up to at least 3-5 hours - then you still have your "active" life on top of that and you're not leaving any room for. You won't get results if you're not eating enough calories to support your training. There does come some water weight gain when initially starting lifting that could be making you feel a little puffy, but not so much that you keep gaining size, and that levels off after a bit. Lifting 3x a week with a couple of runs is fine, so there's not a problem with your routine, other than you aren't eating enough, which can stall your progress, and sometimes even make it seem that you're gaining in size.

You said you did a full reset - how many calories did you work up to and how long did you eat at that level? What did your weight do during your reset? I'm wondering if you truly went high enough with your calories during your reset if you only chose moderate activity level - your TDEE would actually be higher still. If you didn't go up all the way to maintenance, then you didn't complete a full reset and your metabolism would not have healed completely. It's really important to be honest with your activity level.

There are lots of success stories on the website at www.eatmore2weighless.com - please check those out. Every person has a different experience in how their body reacts, but you do have to give the process a fair chance to reap the benefits of EM2WL! Post back with more info and we're happy to help.

I'll just remind that lifting weights doesn't burn as much as equal time say running, and when majority of time is lifting and a decent amount of time at that, it could throw things off.

You don't mention the time spent walking/jogging, or what you mean by staying active otherwise, does that mean 15 min walks at lunch 5 days weekly, or walking dogs, ect?
That could add up.
So you may indeed need to go higher.
But if 3 hrs lifting traditional not circuit training, and only 1 hr walking/jogging total for the week, TDEE may not be that high.

But just remember that fat isn't fast - loss or gain.

So if it's slow weight gain in tummy first not related to feeling bloated from eating a decent amount more, and the math spells out it could be realistic fat gain - you could be eating too much. Just depends on factors above.

Just as chasing a falling metabolism and crashing it into the ground is no good, chasing a TDEE higher until the weight actually matches a value is no good either.
Anyone can make a high TDEE reality eventually, if you gain enough.

You are at least 3-5 hr activity level with all of that activity, possibly the next level higher. We so often underestimate daily activity outside of formal exercise. I only work out max 2 hours a week, but I have to choose 5-6 hr level at a 15% deficit to lose. I kept stalling out when using 3-5 hr and it took me a long time to believe that I still needed to increase my calories even more. Once I finally increased again, my progress and fat loss resumed. I'm a stay home mom and I run around all day with a 3 year old...daily activity does add up.

I'm not sure how many calories you have been eating before now. Are you wanting to try to increase your calories up to a proper amount, or are you not wanting to because of a perceived gain in size? If you slowly increase your calories and give your body time to adjust, you weight and body will stabilize. Maybe what you've been experiencing is trying to pick of weight lifting and eating more at the same time - you're probably gaining water from both lifting and increasing calories to quickly.

If you want to get an accurate calorie burn for weight lifting, a HRM is the best way.