I think it´s dying, sadly. Happens to us all.

How are you growing it? Does it always sit in a glass bowl? Is the base mushy? Planting mix is what?

if it is dying, you can root cuttings from it.

I don't grow these but the outer segments don't look stressed as I'd expect if the inner base segments were dying and no longer functioning well. Do the inner base segments normally become woody after a while?

Older stems on big, old Christmas/Thanksgiving cactus do tend to get brown and woody at the base, but in the photo the brown areas on this plant look like they may be a bit soft? Soil looks awfully dense. Plant might do better in a looser faster draining mix. For epiphytic cactus like this, I use a mix of promix hp, orchiata bark, and pumice.

Oh, and if the brown areas are soft, then the best thing to do is root cuttings from the healthy green parts.

Hi all!
Thanks for the feedback. It grows in a plastic container. The picture was in the kitchen sink. Soil is too dense. I’ll fix that. Brown areas are nice and firm. No mush. I moved it’s location about a month ago . I’ll start trimming in case the growth continues.

Hi, my Mother's older TC has the same thing. Long brown woody stems. The plant is normal and healthy. This happens to the plant as it gets older from what I understand. I would try rooting some cuttings in a separate pot if you love the flower on this plant. The green leaves look healthy, firm and shiny!