The only noticeable interruption in 27L landings yesterday, between the 3pm swap and a change to easterlies at 9pm, was for 10 minutes from around 15:20.
If you wait a day or so, WebTrak should be able to tell you what happened, though not why.
Three GAs in a row is pretty unusual, but not unknown, last time I recall noticing that was mid-December last.
Looks like there were in fact
4 consecutive missed approaches on Wednesday afternoon.
BAW639 (A320 G-EUUT) landed on 27L at 1516 local, and presumably failed to vacate the runway for some reason. The next two inbounds, BAW268 and JAL401, went around from short finals, followed by BAW395B and DLH910 which both broke off their approaches at about 4 DME. BAW891, which was next, was swapped to 27R.
All 4 GAs subsequently landed on the re-opened 27L, starting with BAW395B at 1528.
Doesn't look like a brake/hydraulics issue on this occasion as the A320 in question went back out on the 1645 departure to Barcelona.