It's completely normal that your progress starts stalling after 8 months of newbie gains while being on a cut.

If you want to continue your fat loss journey, focus on your diet: keep your protein intake high and don't be in a too drastic but steady caloric deficit, prolonging the diet forever is not going to lead you anywhere.

Training is secondary for you right now, don't change programs and KISS (keep it simple, stupid).

Seriously, you might not see any gains anymore until you are done cutting, no matter which program you do, overthinking this will only frustrate you. Remind yourself that you came a long way but that this is a long term thing, with one step at a time. Do your curls however you like (just not in the squat rack), but stop fucking around with them.

You’ve been on a calorie deficit for 8 months, you shouldn’t really expect any strength or muscle gains at this point. Just lift to maintain what you have until you finish your cut, then focus on strength and size gains on a small calorie surplus (300-500 calories max).

When you say you’ve been progressing very little, what precisely do you mean? Weight loss? Strength gains? Bicep strength specifically?

I'm only an beginner-intermediate lifter, so take all of what I'm saying with a grain of salt.

Ultimately your gains will depend on Time under tension, assuming you're getting enough rest and nutrition, especially protein. You don't necessarily have to keep adding weights since there's other variables you can adjust like rest time, reps, speed (slower), etc. I can't stress rest and nutrition enough, any time I plateau it's usually because I'm not getting enough protein. Also make sure not to overwork your muscles, they need rest to recover and grow.

If you're focusing on strength (and not hypertrophy or endurance), then you could add other exercises which work your biceps. For instance, deadlifts put a lot of load on your biceps and will shoot up your strength much more when used alongside your curls. To put it bluntly, with an example you're often going to get more bicep gains from a 200lb deadlift than a 30lb curl (MASSIVELY oversimplifying here!). Of course, this only applies if you have already trained extensively on these lifts, they can lead to injury otherwise.

Additionally, there are often bottlenecks to a particular muscle's growth if its supporting muscles, tendons, etc. aren't strong enough. Focusing on the supporting muscles around your biceps should help unlock some gains too.

Another thing to consider is the principle of progressive adaptation. If you're consistently going to the gym and focusing on perfect form, you should always progressively increase your load to prevent your muscles from hitting a wall. This does not mean you have to keep increasing weights, rather adding different movements, playing with rest time in between sets, etc. If you hit a hard wall, don't shy away from reducing your weights and starting a ramp up again, this lets your overworked tendons rest, any weak spots to catch up and builds momentum.

Hope this helps!