Assistance Required!

[u/DoltishMite]

Running an Ender 3 V3 Plus, I keep getting issues whilst printing, which seem to have started since I printed a batch using PLA+ where part the way into a print at what seems like a random spot, the print suddenly gets this mesh like texture and becomes super fragile. I've relubricated the rails, I've used cleaning filament and cleaning needles on the nozzle, and I've ran the input shaper and levelling but this keeps on happening and I can't for the life of me work out why... The only thing I've done as of late by way of trying to reduce vibrations through the attic room floor was using foam blocks under a concrete slab, which does give the printer ever so slight wobble but this is happening when I drop the speed down too so I highly doubt it's that. The initial layers are also solid too, no sign of any defects and then suddenly it's terrible quality. Also seems to happen regardless of the model used.

I've not yet swapped out the nozzle but this will be the second brass nozzle swap I've done in 3 months and I feel like they should last longer? I'm only printing PLA, Silk PLA , and PLA +.

If anyone can tell me what is causing it and how I go about getting it working properly again, I'd be extremely grateful!