What's about going a little bit more deep and check (both) 1920's logs? I presume you setup them both with IP Management address (that's on Default VLAN, generally).
What's about providing informations about (a) 1920 Switches running software versions and actual running configurations (to diagnose what's happening on the CheckPoint Firewall <--> 1920 link, first of all), (b) CheckPoint connected port settings and (c) how did you setup the link between both 1920s (I imagine you configured both involved ports as Port Type "Trunk" since both ports are intended to interconnect Switches and not edge devices like happen on Port Type "Access" set ports).
Generally HPE OfficeConnect 1920 ports default setting is set to "Auto" (for Port Speed recognition), that means the Switch tries auto-negotiation with remote peer (host, in your case the Firewall) on each port.
What's about also checking Duplex Mode (Full-/Half-Duplex) on all involved ends?
The HPE OfficeConnect 1920 Switch series is pretty stable if correctly configured...
Edit: this post should be definitley moved into "Comware based" Switches category or "Web and Unmanaged" (since it belongs to Smart Managed switches familiy) because HPE OfficeConnect 1920 Switch series is not based on HP ProVision OS (used on old HP ProCurve and into new Aruba, rebranded into ArubaOS-Switch).