From what I can make out it looks like El Al have lost their historic late evening slots at LTN this summer.
The initial co-ordination report for LTN shows El Al having been allocated only 12 slots per week (6 pairs), increasing to 16 from late June.
Total 422 slots. - They requested 22 slots per week (11 pairs) which they're selling tickets for.
The STN slots are 10 per week (5 pairs) for the full season operating late evening.
Total 310 slots.
That still appears to be the case:
S2023-Permitted-Slot-Returns-as-per-the-UK-slot-Regulation.pdf (acl-uk.org)
I imagine they're hoping to secure the remaining slots at LTN, or else I guess we may end up seeing some of them at STN.