Poop in clothes post training

[user1465146157]

Has anyone else has this -
My LO is 3, potty trained now for about 6 solid months, wees and poops on the toilet and asks to go, really going well.

Then all of a sudden this past week, every single day she goes under the table and poops in her pants!

She often sort of smiles about it, has no reaction when we ask why she's not going to the toilet anymore. I have a feeling it's since the covid changes and having to stay in a lot more? Just because it's a big change to her usual routine?
But I really don't know.

Advice needed on how to stop this but also how to react - don't want to be upset with her or make her feel bad but also don't want to encourage or make it seem okay?

Help!

I'd say it probably is due to the stress of a big change without any proper transition (not that that's anybody's fault). Just keep encouraging her to go to the toilet, maybe put in place a reward system such as for every poo done on the toilet she gets a sticker/star and then at the end of the week if she's got x number of stickers (the number of poos done usually in a week minus 2 for leeway I'd say) she gets a treat such as favourite meal or pudding, watching her favourite movie, or whatever would excite her that you can do at the minute.
When she does go in her underwear don't react negatively, just do what you would have done during training which is "oh dear let's get you cleaned up. Hopefully next time you'll remember to go to the toilet" all done with a smile and reassurance she isn't in trouble (some children have a few accidents, see that their parents don't like them having accidents but then get too scared to try going to the toilet and it's a vicious cycle).