Cura 3.5 supports 'inside' when unnecessary

[timgr 0]

I swear I used an older version to print this device and didn't have the problem I'm now facing with 3.5.

 

This is the model (find it here if you want to try this on your own.) Note that there is a hollow tube that runs in the base that connects each side. The knurled portion is supposed to turn freely so you can screw it onto a soap bottle.

 

After slicing, with supports turned on (set to 'everywhere'/70degrees), it looks like this.

 

The supports, because of 'everywhere', look correct and are doing what I would expect:

 

However, if I continue to scan down into the tube below it, you can see that supports are added there, unnecessarily.

 

I would swear that the last time I printed this, it did NOT have that in the middle.

 

In fact, I just realized, I use Octoprint, and the gcode file is still stored there from 7 months back (";Generated with Cura_SteamEngine 3.2.1".) Here's what it looks like when printing the tunnel layer:

 

And just to prove that it was still printing the layer of support between the body and the knurled knob:

 

We have a change of behaviour/bug here, and its preventing me from reslicing this object. I don't think it's me, although if it is, I'd love someone to point out where I'm being goofy.

 

I cannot even use the support blocker to fix it. The only place I can put the support blocker to get it to NOT generate the supports in the tunnel is by blocking the supports right under the knurled knob.

 

Grrrrrrr. Ideas? Methods to fix this? Can I install older cura at the same time as newer cura?

[timgr 0]

In fact, I just installed 3.4.1 and sliced it there with the same settings, and it does NOT place the supports in the tunnel.

 

[burtoogle 516]

Yes, this does look like a regression. Please open an issue at https://github.com/Ultimaker/Cura

[timgr 0]

Thanks. I didn't know where to go to write up bugs, so the link was helpful. The thing is, someone posted this same bug (different model, issue #4583) about 19 hours ago, so it's not just me. ? 

 

I added my files to the bug report in case they're needed. Hoping to see this fixed sooner rather than later.