(SSL: error:1409441A:SSL routines:ssl3_read_bytes:tlsv1 alert decode error:SSL alert number 50) while reading response header from upstream

[Liam Moncur]

Hey,
I am seeing an issue where nginx seems to get stuck in a loop soon after the above error. From the debug I am seeing:

2020/04/02 14:09:10 [error] 12875#12875: *338 SSL_read() failed (SSL: error:1409441A:SSL routines:ssl3_read_bytes:tlsv1 alert decode error:SSL alert number 50) while reading response header from upstream, client: 2a00:23c6:8238:6501:54e9:28f4:54e:1a91, server: www.findafishingboat.com, request: "GET /boat-list/fishing-boats-for-sale-over-15m HTTP/2.0", upstream: "https://194.39.167.98:443/boat-list/fishing-boats-for-sale-over-15m", host: "www.findafishingboat.com"

Then shortly after I get a loop of the following:

2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter 0000000000000000
2020/04/02 14:09:10 [debug] 12875#12875: *338 http copy filter: -2 "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http output filter "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http copy filter: "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 lua capture body filter, uri "/boat-list/fishing-boats-for-sale-over-15m"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http postpone filter "/boat-list/fishing-boats-for-sale-over-15m?" 0000000000000000
2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter: l:0 f:0 s:0
2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter limit 0
2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter 0000000000000000
2020/04/02 14:09:10 [debug] 12875#12875: *338 http copy filter: -2 "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http output filter "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http copy filter: "/boat-list/fishing-boats-for-sale-over-15m?"
2020/04/02 14:09:10 [debug] 12875#12875: *338 lua capture body filter, uri "/boat-list/fishing-boats-for-sale-over-15m"
2020/04/02 14:09:10 [debug] 12875#12875: *338 http postpone filter "/boat-list/fishing-boats-for-sale-over-15m?" 0000000000000000
2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter: l:0 f:0 s:0
2020/04/02 14:09:10 [debug] 12875#12875: *338 http write filter limit 0

Any thoughts would be lovely.

Thanks,
Liam