I havent started migrating my RG186’s yet so dont have 1st hand experience and mine are running a mix of earlier firmware builds but wonder if anything in this thread might help you
Also, as looks like you have set Basic-Station (gateway mode sbs?) am unsure if that works with your earlier selection of ‘The Things Legacy - EU’ - what other options do you see for this that might work with B-S?
Also I know with other B-S GW’s (i.e. TTIG’s) there were issues with connection keep alive (that have evolved over the last year or two!) hence asking if there is a known good node in the area - it may be you need to see traffic - in your case to initiate connection vs keep one alive - perhaps others can comment on this…
…I really need to crack on with moving more of my (Laird) GW’s now so perhaps I will find more to offer you myself in coming days…