Mmmm...from configuration file the HPE 3800-24G-2SFP+ Switch (J9585A) physical port 25 (it's the first 10GbE port of two, is it right?) is used as uplink port to the HPE OfficeConnect 1920-24G switch...but on this latter one what port was used as uplink terminating port?
I ask because HPE OfficeConnect 1920 Switch Series hasn't 10GbE Ports (Ports and Slots are for 1GbE at maximum) so you were forced to use, on both ends, physical ports running at Gigabit Ethernet speed only at best (that's mandatory on the HPE 1920 side). Is that right?
Question: 10GbE Port 25 and 26 on HPE 3800 can go at 1GbE? in other terms do those ports admit 1GbE/10GbE operation or only 10GbE?
Have you set both uplink end ports with "Port Type" of type "Trunk" instead of type "Access" permitting VLAN Id 1 to pass? I ask because HPE 3800 Port 25 and HPE 1920 Port x are uplinked so Port Type should be set of type "Trunk" (at least this is the nomenclature and port settings that is recommended on HPE 1920 side, since it is a Comware 5.20 operating system based Switch).
On HPE 1920 consult User Guide to see how to set the port used as uplink to HPE 3800 of type "Trunk" permitting VLAN Id 1 (VLAN Id 1 is default untagged on all ports so it should be very simple as changing type "Access" to type "Trunk" for the "Port Type" on the port considered for the uplink).
The HPE 3800 is ProVision operating system based and uses another type of nomenclature to define an uplink port to another switch, generally it is sufficient to configure the VLAN Id 1 to be untagged on the physical port you will use to uplink to another switch (eventually specifiying other tagged VLAN Ids that uplink port would let to flow):
HPE3800(config)#vlan 1
HPE3800(config-vlan)#untagged 25
Then consider to update both Firmware images (R1108 of HPE 1920 is quite old, latest is R1117 or eventually R1116 | KA.15.03.3015 ...what? is that correct? looking here no KA.15.03.3015 was listed so, probably, it is older than the oldest liste which is KA.15.09.0009...by the way latest software release for 16.04 Software Branch of KA Product Line is actually the recent KA.16.04.0008...so, if I were you, I would pay a close attention to my Switch(es) firmware(es) before trying or doing other configurations).
You should configure your uplink between HPE 3800 and HPE 1920 as described here