I just upgraded my CRS310-1G-5S-4S+ to 7.14.3 and I think the configuration for the cooling fan isn't working... I tried changing settings via Health to see if I could manipulate it, but it looks like it's just going full speed... how do I report this bug to the development team?

Thank you! I just posted a bug report and will follow up with support.

I also had exactly the same problem after upgrading - then tried upgrading to current testing release, did not solve the issue, now I'm stepping back through stable releases trying to fix it - I'm back to 7.10 and the fan is still running flat out even with internal temps at 28C, so I suspect it might need a config reset too. Note that this is just with a cable in the ethernet port, nothing in the SFP ports at all.

Edit: config reset fixed it with an old RouterOS installed, upgrade to current stable with a clean config brought the issue back, upgrade to current testing ( 7.15rc4 ) fixed the issue again. Can only assume the fan config got poisoned by the original upgrade to stable.

I have the same issue.

7.14.3 behaviour:
"Fan Min Speed Percent" - RPM
12 (default) - 14000
1 - 14000
0 - 0

7.15rc4 behaviour:
"Fan Min Speed Percent" - RPM
12 - 14000
1 - 14000
0 (default) - 0

Do I understand this correctly? Either this device cannot handle this setting, or it cannot control the fan speed at all?

UPDATE1: According to this post (viewtopic.php?t=205246#p1061407), this device only supports fan on or off, so the minimum fan speed should be set to 0.
I guess this means changing this value will make it work as intended on 7.14.3 too.

UPDATE2: I did some testing, and both on 7.14.3 and on 7.15rc4 the fan turns on at full speed when temps are above the target temperature. So I guess the only thing changed is the default value for the minimum fan speed on this device.

My conclusion is that you can use 7.14.3 safely, you just have to set the minimum fan speed to 0.