I can't say I have seen that before.
My thinking was that you may have been encountering a Chrome (61+) specific defect, CSCvg20776, which requires a cop file for SocialMiner.
This is a defect associated with Chrome versions 61 and up ( CSCvg20776 ). There has been a cop file published for SocialMiner to address this.
https://software.cisco.com/download/release.html?mdfid=283613136&flowid=73189&softwareid=283812550&rel...
Yes. Finesse IP Phone Agent (FIPPA) can be used to login to a phone only setup.
https://www.cisco.com/c/en/us/support/docs/customer-collaboration/unified-contact-center-express/212115-Configure-and-Troubleshoot-Finesse-IP-Ph.html
Building on what Lulian said, I would preconfigure the 3850s. If the vlan database is large it would be easier to configure the 3750s to pass the vlans. I would be very careful in configuring VTP in your production network, but it would make the tr...