Multi Building Single ISP FIBER FEED config help

I think your instinct is correct.  "It's the switches".

Time for a visit to Amazon. Check this out:

https://www.tp-link.com/us/support/faq/291/ 

It appears that the "RJ45 Console Port" is an RS-232 interface.  (Wow.  That "takes me back" to the 20th century!). What Search Amazon for "rj45 console cable".  One of the hits specifically mentions TP-Liink.

Than, there is Step 4:

Step 4 Launching the CLI

Enter the username and password, then you can manage the switch. Please refer to the User Guide, and CLI Reference Guide, which can be found on the support page for your switch model.

These business class switches appear to be "overkill" for this application.  If it was a Cat6 Ethernet cable connecting house to barn, then simple "unmanaged" gigabit switches would be perfect for this situation.   (Don't suppose that fiber cable is loose in a conduit and could be used to fish a CAT6 cable through?)

I have found TP-Link support forums fairly helpful.  Perhaps it would be a good idea to post a question there asking, "where the heck is the User Guide and CLI-Reference Guide for this switch????"

i may try to see if something like this would work, 

https://www.amazon.com/gp/product/B09P4ZS4QN/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

have one cat6 connection to media converter  - fiber - to house into the other media converter, then into orbi960 at house

then out of the 960 at house i could just cat6 into an unmanaged switch for house distribution.

then just run a second cat6 out of the orbi750r to the previous unmanaged standard 8 port switch it was originally on in the barn.

or would there be a netgear unmanaged switch for each side of the fiber i could use with SFP or SFP+

Bypassing both of those TP-Link switches with a pair of media converters would "do the trick".

It is important to match the converter with the type of fiber that is installed (multi-mode vs. single-mode).

Bummer that getting into the management console of the switches is so complicated.

Have not found an unmanaged Netgear switch with SFP capability.  This Trendnet box is available on Amazon:

https://www.amazon.com/TRENDnet-Switching-Capacity-Protection-TEG-S51SFP/dp/B019IHWSF0/ref=sr_1_16?crid=2IHPMLW3U2LDT&keywords=yuanLay+gigabit+switch+sfp&qid=1683239721&s=electronics&sprefix=yuanlay+gigabit+switch+sfp%2Celectronics%2C132&sr=1-16 

Adding a Trendnet SFP of the proper type (multi mode vs. single mode) brings it to about $77 per end.  (Still less costly than digging another trench to install Cat6 cable.)

Using that pair of converters is thus less than half the cost of this alternative.  There remains the problem of how to use those existing TP-Link switches.  If something plugged directly into a switch port does not get internet, "something is not right!?

It's either a VLAN setting on the Orbi router or "something" in the managed switch.

the media converters should arrive this weekend, so hopefully i'll be able to give them a try, will update my findings.

ok the media converter got me Access into the house, Orbi960 is now in AP mode, but i have not done anything as far as DMZ's and or static ip's 

issue i'm now having is devices like my ring won't connect,  

i plan to have all my home smart devices on the "guest" network. 

for ring devices i get through to the final step and then it just never connects.

however on something like my garage doors.   i'm able to connect, however it seems to be broken to some extent.  as i can open my garage doors with the app but can't close them.

however all sensors etc. when pressing actual wall close button allow doors to close.

Try using the IoT network for your Ring and IoT devices. It's what it's there for.