have these menu items – where you are using the [wppizza single=’x’] shortcode been assigned to a category ?

which version of wppizza are you using ?

the thing is, a 502 could be pretty much anything
(https://kinsta.com/blog/502-bad-gateway/)
only the server logs will be able to tell you the issue
and as that script gets accessed and – most likely – throws the 502 before it executed and.or wordpress gets even loaded only the server logs will be able to shed light on this

that’s assuming it’s not some other plugin that throws this 502 of course (or perhaps some htaccess file settings or whatnot)

if i understand you correctly , this also seems to be a recent issue you end . as the gateway has not changed for months (and does no such thing as setting or not TLS etc etc or any such thing) I would suggest the issue is elsewhere

sure, if it turns out i am wrong (although i cannot see how) i would be happy to stand corrected and fix things if needs be , but without anyone providing proof (or indeed details) to that effect, there’s nothing for me to do here from what i can see

i can assure you that the wppizza plugin does not block anything – that would be stupid (but some other plugins might, or your hosting company , or a firewall, or your file permissions mess things up etc etc .)
suffice to say your hosting company (or server admin) should be the ones that are able to tell you why it’s a 502. nobody else will as nobody else has access to the server logs

worldpay only tells you the symptoms (and from what i can see, they are not at fault here)
they are trying to send info back to your server but the server responds with 502. they will not be able to know anything else .

a personal opinion – you could do what you like of course: i would SERIOUSLY reconsider using godaddy and find some – in fact any – other host (just from experience dealing with some different sites hosted on godadday – wppizza related or not)

you pretty much answered your own question . (there ar =e likely to be a bunch of other setting that would need to be the same across sites…)
at a minimum, you will also have to synchronise the coupon codes across sites (and keep them synched) as they will keep track of the usage of codes.
and even if you manage to do all that , it would only work – if at all – in a multisite setup as multisites share user tables/ids

see
https://support.wp-pizza.com/topic/show-deliver-picked-time-in-admin-order-history/
(yeah, i should have replied here to start off with.. never mind)

with coupons and discounts you would have to set the appropriate (simple) discount for each item or multiple items (you can set multiple discounts of course as appropriate). However, depending on what exactly your prices are supposed to be, that won’t be a fast job either.

That said, i suspect you do not actually really want to apply discounts, but really have the item prices reduced to start off with between certain times, in which case the way to go about that is to write some script that filters the custom post type (in this case wppizza) meta data – that’s where prices are stored for an item.

you should consult the wordpress codex regarding filtering post type meta data

Same applies here too though. There is no “simple/fast” shortcut to do this sort of thing

something is clearly missing here in your question (i.e the conditionals)…..

what you are describing is not a discount but simply something that’s half the price of what it is, so simply set the price to start off with to be 50% of what you have currently

there are no provisions for that unless you edit core plugin files directly (which is never, ever a good idea)

when you use distances, the plugin does not care what the postcodes are and the labels – although must be unique – have no relation to the postcodes and you can simply name them whatever you want (i.e upto3 and upto5 for example)