QuestionA7 IV under floodlights, focus is fine but files look mushy?

Hello all. I've been shooting my nephew's under-14s rugby on Saturday mornings since January, but the evening training sessions are under floodlights now and I'm struggling. A7 IV with the 70-200 f/4. Settings are 1/1000, f/4, auto ISO, and it's ending up around ISO 12800.

Focus seems to land on the right player, but the files look soft and smeary when I zoom in, almost like a watercolour. Is that just the ISO? Would I be better off dropping the shutter speed? Any advice gratefully received. Thank you.

Watercolour look is in-camera noise reduction on the JPEGs, not the sensor. Shoot RAW and run AI denoise in Lightroom, at 12800 the difference is big.

Also for training 1/500 is enough for most of the action unless it's a tackle or a sprint. That's one stop, so ISO 6400. I shoot my son's football under lights at 1/640 and it works fine.

ravenshoots said:

almost like a watercolour

yeah thats jpeg noise reduction 100%. raw + denoise and 12800 is fine honestly, i shoot dark clubs at 25600 on an original r6 and bands use them

I am shooting JPEG, yes, I didn't realise the camera was doing anything to them. I'll switch to RAW and try 1/500 at Thursday's session and report back. Will Lightroom's denoise work on the A7 IV files, or do I need something else? Thank you both.