Toilet training advice

Hi everyone, looking for some advice (and maybe reassurance!).

We have a Labrador puppy who turns 20 weeks old this Friday, and toilet training has been much harder than we expected. We’ve been really consistent — taking him out to the garden as soon as he wakes up, after meals, after naps, and after playtime.

He’s had a couple of accidents on our carpet, and now he seems to actively prefer going there. He does circle beforehand, but it’s always on the carpet. As soon as we see him start circling, we take him straight outside — but he often just runs back in and tries to go on the carpet again. Sometimes this cycle repeats multiple times, and it feels like we’re getting nowhere.

When he toilets outside, we give lots of praise and high-value treats immediately, but it doesn’t seem to be fully clicking yet.

For extra context:

• We tried toilet pads, but he just rips them up.
• We also tried bell training, which unfortunately didn’t work for him.
• Very occasionally he will tell us he needs to go out, but it’s rare.

A few questions:

• Is this normal for a nearly 5-month-old Lab?
• How do we break the carpet preference?
• Are we accidentally reinforcing the run-back-inside behaviour?
• Should he be signalling more reliably at this age?

We’re trying really hard to set him up for success, so any tips, reassurance, or things that worked for your puppies would be hugely appreciated. Thank you!