I used to take Lexapro (escitalopram) and for my sleep and it used to make me feel sleepy. Now, it doesn't have any effect. Is it normal to have a hard time sleeping at night with Lexapro (escitalopram)?

LExapro (escitalopram) Lexapro (escitalopram) enhances serotonin which in most people causes insomnia due to its rem off properties if i recall correctly, so usually given in the morning, some people need serotonin for sleep and perhaps you have built up tolerance and try taking it in the morning under md supervision.
Lexapro (escitalopram) Discuss with your prescribing doctor possible dose adjustment.
Normal. That can be normal. If the medication keeps you awake then take it in the morning. Discuss all side affects with your physician and take it as prescribed.